Update JSoup to version 1.16.2.
This requires renaming `Whitelist` to `Safelist`,
because the class name was changed in version 1.15.1
in a breaking change.

The calculation of a MD5 and SHA-1 sum are all message digest implementations.
Instead or replicating the same code over and over again, provide a
common function for message digest calculation which can do this for
different algorithms based on the algorithm name passed as a parameter.

Then replace the existing `getMD5` and `getSHA1` functions by calling
the common function passing the respective algorithm name.

The page shown for an empty repository lists suggestions for Git clients,
mostly GUI ones, and links to their web pages.

The TortoiseGit client entry is removed since the URL is no longer valid.
The excellent client Fork is added to the closed source clients
section.

This commit also cleans up some other entries, fixing broken tags,
escaping ampersands and removing outdated or wrong information.

The currently used translation of "fork" is ambiguous, using the same
word as for "branch".

Fixes #1448

Replace the links in NOTICE to the closed down Google Code
(code.google.com) with their Github counterparts where the projects
moved to.

Gitblit used to download dependencies upon first start. This has since
long been changed and everything is bundled with Gitblit now. So reflect
this in the design.mkd document, which still said they would be
downloaded.

Adjust other references to the old 'gitblit' organisation on Github to
point to the new 'gitblit-org' organisation.

The update of JGit broke pushes to tickets. The ReceiveCommand now
requires all three arguments, oldId, newId and name, to be not null.
The ticket code handling pushes to tickets left name and old id as
null in certain cases. This is fixed by always providing values.

The merge step for using `pt` added the wrong text to the copy button.

Donated by @piradix

This fixes incorrect encodings in the _de language file which makes
the pages crash.

Adding style element `max-width:inherit` as suggested by @piradix, which
makes the access restriction icon be part of the URL box again.
This fixes #1437

The `clippy.swf` Flash program is no longer needed and can be deleted.
The configuration property is now incorrectly named, but we keep the
name and update the documentation. Maybe it could be completely deleted
one day, when the clipboard.js solution is known to work and be universally
supported.

The ticket page also has some copy-to-clipboard buttons, which get
updated to work with JS instead of SWF.

This is not the ideal version, since the height is too low for the tooltip
used for the drop-down menus. Probably has something to do with the
container or something. But at least something is there now, even if
not the most beautiful.

Shockwave Flash is dead. But Gitblit still uses it to copy the repository
URLs to the clip board. Which doesn't work anymore since no browser uses
Flash anymore, so this has degraded disgracefully.

Instead, we can use JavaScript to copy directly to the clipboard, now
that there are APIs for it. So replace the use of clippy.swf on the
repository page with clipboard.js[1]. This right now only has the
functionality to copy to clipboard but now visual feedback, yet.

This addresses GH issue #1241.

[1] https://clipboardjs.com

Adding Ed25519 keys brings the problem that with the library currently
used, the PublicKey instance of that key is not serialisable. This
results in an exception when wicket tries to cache the UsersPage.
So change the SshKeysPanel so that the PublicKey object is removed
from the `SshKey` when the panel is detached. It can be regenerated from
the raw key data.

This updates Jetty to the latest 9.x version as of writing. The 9.x is
still running on Java 8. The update needs two code changes.

`SessionManager` was replaced with `SessionHandler`. This was documented
in the Jetty documentation.

Adding the `GitblitContext` to the `WebAppContext` will result in two
instances getting created, because the code was changed that prevents
instantiation the same listener class multiple times. (The second time
is when the web.xml is read.) Instead, it must be added to the servlet
handler of the `WebAppContext`. This results in properly adhering to the
changed internal startup flow.

Updating Jetty also resolves #1409.

Jetty 9.3 changed the `setHandler` on the ServletContextHandler to no
longer automatically detect SecurityHandler, SessionHandler, etc. It
simply passes on the setHandler request to the ContextHandler class
(with a warning logged). So make sure to explicitly use the method
`setSecurityHandler` to set the ContraintSecurityHandler responsible
for the http -> https redirection.

Catch all exceptions, and not just IOExceptions, from bugtraq formatter.
If an exception is caught, ignore the bugtraq handling of the commit
message and show the plain message. Way better then not showing anything
just because something broke in bugtraq.

Reading the encoding of a commit can result in a Unsupported- or
IllegalCharsetException. This happens when for whatever reason the
commit has an encoding recorded that the system doesn't understand.
Instead of completely failing, fallback to UTF-8.

Updating JGit fixed the issue that a commit in a repo with an unknown
character set throws an exception. This would crash the RepositoryManager.
The extra handling, which patches JGit classes during runtime is completely
removed.

Unknown encodings may cause gitblit to fail to start. This modification
injects a wrapper class in the JGit internal to fake a valid return value.

Sync with upstream @ https://github.com/mstrap/bugtraq

Since it is a pest to get rid of a Wicket FeedbackMessage in an AJAX target,
change the code to use an extra label that can provide feedback if the
key could not be parsed or was empty.

if key is empty of can not be parsed, form did provide any feedback to
user before

When a user had a certificate, i.e. an entry in the Gitblit Authority
database, but the user was deleted from the Gitblit database, then the
Authority application crashes upon loading. This patch prevents the
crash. The deleted user is no longer shown in the Authority. But the
database entry still is kept. This should be improved to show deleted
users and give the possibility to delete them from the Authority's
database.

This fixes #1359

Fix a null pointer access in the `toString` method for a freshly created
`FileSettings`.

Since we now do not generate a DSA host key file anymore, but keep it in
the list of potential keys so that existing keys still work, it can
happen that the files for DSA (and Ed25519) are getting loaded but they
do not exist. This results in an error in the log.
So instead check if the file exists and only try to load files that
exist. This prevents from errors (which are none) being spammed in the
log.

Create new host keys, one with ECDSA and one with Ed25519 algorithms.
For the Ed25519 currently the EdDSA library from i2p is used. This
requires some quirks, compared to a modern BouncyCastle. But the SSHD
library used cannot use BouncyCastle yet for Ed25519.

No DSA key is generated anymore, but we still support existing ones.

The version 1.69 is chosen instead of 1.70, because the moxie build
would not download the jars, trying to download `...1.7.jar` instead.

Three class deprecations are fixed. `PEMWriter` and `X509Extension`
are replaced with their drop-in replacements `JcaPEMWriter` and
`Extension`. The `PasswordFinder` deprecation note says that "it is
no longer used". It also was never used in Gitblit's code, so it is
removed from the key par provider class.

- new python 3 versions warn/errors about this usage

(cherry picked from commit d8fbdda2ab3fa48e92bdf37399d4b75c48409c5c@rpardini:master)

# Conflicts:
#	.classpath
#	build.moxie
#	src/test/java/com/gitblit/tests/SshUnitTest.java

Instead of adding another setting and having to explain how the new one
and the existing `requireClientCertificates` setting are interdependent,
let's use the existing setting and add new values.

It is changed from a boolean to a string, with the values `required`,
`optional` and `disabled`. To keep backward compatibility with the old
values, the `true` value is mapped to `required` and the `false` value
is mapped to `optional`.

This also removes the additional Set. What changes is that the order of
the repositories is kept, but the resulting list will have user and team
permissions intertwined.

These show more clearly what the code is supposed to do.

Tabs are not always 4 spaces large. It completes the line to the 4th
character.