Add Ant tasks and macros to deploy binaries to GitHub,
using GitHub's releases.

Adds an Awk script to extract GH flavoured markdown release notes
from the release.moxie file.

Adds `ok.sh` to the repository so that it is readily available.
This is a Bourne shell GitHub API client, used to create a release
on GitHub and upload the binaries.

They will need to be called with the classpath and main class now,
instead of simply using the Jar.

The (moxie and other) Launcher do not work with Java 9 and later anymore.
It used to dynamically extend the classpath, misusing an internal
interface of the `URLClassLoader`. This is no longer possible since Java 9,
which closed that path and does not offer any way to dynamically extend
the classpath during runtime.

So the choice is between providing one large Jar with everything in it,
providing a Jar that has the Jars in `ext` listed explicitly in its
manifest, and specifying the classpath on the command line where
the `ext` directory can be added and all contained jar files will
be put on the classpath.

The motivation for the Launcher class was to be able to simply drop
new jar files into a directory and they will be picked up at the
application start, without having to specify a classpath. We opt
for solution three here. This way jar files can still be dropped
into the ext directory, albeit the directory needs to be added to
the classpath on the command line. Unfortunately using a wildcard
is not possible in the manifest file. We change the calls in the
script files accordingly. This seems like a good compromise,
since no one will run the application manually typing the whole
commandline anyway.

This also does away with the splash screen, by the way. Again,
doesn't seem like a big loss, as I don't think it was ever shown
for the Authority.

Personally, I am not convinced that it is the best way, because
I don't really think that the use case of dropping whatever jar
files into the `ext` directory is a valid one that happened a lot.

This does not yet fix the client programs, which still use a
Launcher. Maybe for them a all-in-one Jar is a better solution.

Fixes #1262
Fixes #1294

Integrate the `PasswordHash` class and subclass in the user
and password editing and authentication. Replaces the old code and
the previous `SecurePasswordHashingUtils` class.

e.g.: https://localhost:8443/rpc/?req=LIST_REPOSITORY_BRANCHES&name=repo.git

Fix #1184

Addresses #1166

+ Filestore listing filtered by user view permissions
+ Configuration help for filestore relocated to website files
+ Added migration example

+ Adds standard logging for all authentication providers
+ Updates help page to use default GitBlit SSH port

The RPC URL should be `/rpc/?` and not `/rpc?` according to
https://groups.google.com/d/msg/gitblit/Ajp2gR3B2bM/AXg6wIf21eIJ

In AuthenticationManager:385, only `provider instanceof UsernamePasswordAuthenticationProvider` will be called

This change also ties the plugin manager into the Wicket framework and
allows plugins to contribute and mount new pages which are linked by the
top navbar and repository navbar extensions.