Gitiles: Implement Buck driven build

Until extension system is released by Buck team [1], factor out
existing Buck building blocks as Bucklets in standalone git
repository and reuse it as Git submodule to implement Buck driven
build [2].

To build gitiles `gitiles` target is used:

  buck build gitiles

To build servlet, sources and javadoc in addition, `all` target is used:

  buck build all

that produces:

  buck-out/gen/gitiles.war
  buck-out/gen/servlet.jar
  buck-out/gen/src.jar
  buck-out/gen/javadoc.jar

To execute the tests:

  buck test --all

To generate eclipse project:

  bucklets/tools/eclipse.py

To fetch sources for all dependent libraries too:

  bucklets/tools/eclipse.py --src

To install gitiles-servlet into local Maven repository:

  buck build mvn_install

To deploy gitiles-servlet into remote Maven repository:

  buck build mvn_deploy

[1] http://stackoverflow.com/questions/16681527/buck-vs-gradle-pros-and-cons-for-android-build-systems
[2] https://gerrit.googlesource.com/bucklets

Change-Id: Ib824dac6423d69c298f9c30ed7a0c05b4d6447c0

lib/slf4j/BUCK

diff --git a/lib/slf4j/BUCK b/lib/slf4j/BUCK
new file mode 100644
index 0000000..b04b670
--- /dev/null
+++ b/lib/slf4j/BUCK
@@ -0,0 +1,19 @@
+include_defs('//bucklets/maven_jar.bucklet')
+
+VERS = '1.6.1'
+
+maven_jar(
+  name = 'slf4j-api',
+  id = 'org.slf4j:slf4j-api:' + VERS,
+  sha1 = '6f3b8a24bf970f17289b234284c94f43eb42f0e4',
+  visibility = ['PUBLIC'],
+)
+
+
+maven_jar(
+  name = 'slf4j-simple',
+  id = 'org.slf4j:slf4j-simple:' + VERS,
+  sha1 = '58e59bfb3e247097b8122243b3bfe0049c8cfae8',
+  deps = [':slf4j-api'],
+  visibility = ['PUBLIC'],
+)