Remove support for japicmp from Gradle build

I now spent a few hours trying to make it work and the Gradle support is
simply not production-ready and also not maintained, it triggers various
strange errors and does not supporting the usual Gradle conventions.

So I do not want to spend more time on it, feel free to revive it if you know how
to make this work properly.

git-svn-id: 13f79535-47bb-0310-9956-ffa450edef68
10 files changed