Add a simple ssh git server based on Apache MINA sshd, and use it
in new tests that verify ssh operations and in particular a number
of bugs that had cropped up over time in JSch.

The git server supports fetching only, and sftp access.

The tests are all in an abstract base class; the concrete JschSshTest
class only provides ssh-specific test setup. So the same tests could
be run easily also with some other ssh client.

Bug: 520927
Change-Id: Ide6687b717fb497a29fc83f22b07390a26dfce1d
Signed-off-by: Thomas Wolf <thomas.wolf@paranor.ch>

Generating the src list with an unrestricted wildcard causes all
files in the source tree to be included. This results in junk files
such as .orig (generated during merge conflict resolution) to be
included, which causes in a build error:

  in srcs attribute of java_library rule //org.eclipse.jgit:jgit:
  file '//org.eclipse.jgit:src/org/eclipse/jgit/gitrepo/RepoCommand.java.orig'
  is misplaced here (expected .java, .srcjar or .properties).

Modify the globs to only include Java source files.

Change-Id: Iaef3db33ac71d71047cd28acb0378e15cb09ece9
Signed-off-by: David Pursehouse <david.pursehouse@gmail.com>

Only testonly targets (such as tests) need to use junit.

In particular this involves making the toplevel :all rule testonly.
It's not clear to me what that rule is for --- "bazel build //..."
already works to build all targets.  In any case it appears to be for
testing, so marking it as testonly shouldn't be harmful.

Change-Id: I28ff508ab8ce2ec0a0111109110aa9680d30600e

This provides a place to declare visibility restrictions and
transitive dependencies for each library.

Other targets should only declare dependencies on what they directly
use, making dependencies easier to maintain.

Trim the dependencies of org.eclipse.jgit:jgit to follow that rule.
It declares dependencies on Apache httpcomponents and the servlet
API but doesn't use them.

Tested:
* 'bazel build //...' succeeds
* applying the change https://gerrit-review.googlesource.com/90843
  to a copy of Gerrit, following the instructions there, and running
  'bazel test //...' in that copy of Gerrit still succeeds

Change-Id: I3ab958ce8b3227019cdbe4cc81e0f042e1541034

Change-Id: I934114315d2c7cab917f1011b8e55c52367d429f
Signed-off-by: David Pursehouse <david.pursehouse@gmail.com>

The initial implementation only builds the packages consumed by
Gerrit Code Review.

Test build and execution is not implemented.

We prefer to consume maven_jar custom rule from bazlets repository,
for the same reasons as in the Gerrit project:

* Caching artifacts across different clones and projects
* Exposing source classifiers and neverlink artifact

TEST PLAN:

  $ bazel build :all
  $ unzip -t bazel-genfiles/all.zip
  Archive: bazel-genfiles/all.zip
    testing: libjgit-archive.jar      OK
    testing: libjgit-servlet.jar      OK
    testing: libjgit.jar              OK
    testing: libjunit.jar             OK
  No errors detected in compressed data of bazel-genfiles/all.zip.

Change-Id: Ia837ce95d9829fe2515f37b7a04a71a4598672a0
Signed-off-by: David Ostrovsky <david@ostrovsky.org>
Signed-off-by: David Pursehouse <david.pursehouse@gmail.com>