Step 2: Import jars for Gradle dependencies

I got these by running "./gradlew --debug assembleDebug", grabbing the
jars using during javac, and copying them into the repo.  For the aar, I
got the original (unexploded) aar from the support repository.

None of the dependencies in build.gradle are provided scope, so I think
it's okay for us to just include these as normal dependencies.
Step 3: Replace switch statements with if statements

Buck always uses non-constant resource ids when compiling, so we can't
use switch statements with them.  I just used IntelliJ's intention to
convert all of these to if statements (and renamed the switch
variables), and it reformatted some of the code a bit.
Step 4: Add BUCK and .buckconfig files, and update .gitignore
Step 5: Include Buck's support jar for exopackage.

This JAR can be built by running the following from a checkout of Buck:

  buck build //src/com/facebook/buck/android/support:buck-android-support
Step 6: Make the default build be an exopackage