Buck: unsign all jgit jars

Change-Id: I25749b80f2060f3322844cd2b94075acd3874e51
(cherry picked from commit 0b579f89efe2e9889b84f5eb609a9afd422cca44)
Buck: fix api_install rule

Change-Id: I069b52004781b3b1a8d64514da3f2e4da8047816
(cherry picked from commit a3f72e4bb84deb1892e931d850e06f8ee8a55b95)
Enable standalone JavaScript plugins

The idea of 'standalone JavaScript plugins' came during the 'JavaScript
plugins' talk at the Gerrit User Summit.

The main concept is to automatically install and expose all *.js files
that are in Gerrit's plugins/ directory.  This should lower the entry
point barrier for JS developers.

There is one limitation of such plugins: they cannot contribute
additional resources.  When such are required, the implementer should
inline them in JS code or use the gerrit-plugin-js-archetype.

Change-Id: Ibad8c3938c0855fcabe6937fd8b4d508a9a2eac3
Signed-off-by: Dariusz Luksza <dariusz@luksza.org>
Merge "Buck: fix api_install rule" into stable-2.8
Merge branch 'stable-2.8'

* stable-2.8:
  Buck: fix api_install rule
  Buck: unsign all jgit jars
Merge "Enable standalone JavaScript plugins"