Implement Bazel build

To run the tests:

  bazel test //...

To build the Gerrit plugin API, run:

  bazel build gerrit-plugin-api:plugin-api_deploy.jar

To build the Gerrit extension API, run:

  bazel build gerrit-extension-api:extension-api_deploy.jar

TODOs:

Licenses
Reduce visibility (all public for now)
Generate HTML Documentation
Core plugins
gerrit_plugin() rule to build plugins in tree and standalone modes
GWT UI (only gwt_module() skylark rule is provided, no gwt_binary())
PolyGerrit UI
WAR
Publish artifacts to Maven Central
Ask Bazel team to add Gerrit to their CI on ci.bazel.io

Contributed-By: Han-Wen Nienhuys <hanwen@google.com>
Change-Id: I9a86e670882a44a5c966579cdeb8ed79b1590de3

gerrit-cache-h2/BUILD

@@ -0,0 +1,30 @@
+load('//tools/bzl:junit.bzl', 'junit_tests')
+
+java_library(
+  name = 'cache-h2',
+  srcs = glob(['src/main/java/**/*.java']),
+  deps = [
+    '//gerrit-common:server',
+    '//gerrit-extension-api:api',
+    '//gerrit-server:server',
+    '//lib:guava',
+    '//lib:h2',
+    '//lib/guice:guice',
+    '//lib/jgit/org.eclipse.jgit:jgit',
+    '//lib/log:api',
+  ],
+  visibility = ['//visibility:public'],
+)
+
+junit_tests(
+  name = 'tests',
+  srcs = glob(['src/test/java/**/*.java']),
+  deps = [
+    ':cache-h2',
+    '//gerrit-server:server',
+    '//lib:guava',
+    '//lib:h2',
+    '//lib/guice:guice',
+    '//lib:junit',
+  ],
+)