Change versions to 1-perfComp-SNAPSHOT / 3.4-perfComp-SNAPSHOT
Performance improvements

-caching javac compiler instance
-disabling annotation processing while parsing java files
Reintroducing our old Java 7 ANTLR parser.

The official Java parser accessible by the Java Compiler Tree API is too slow.
We will switch back to the official one once we move to Java 8. It is not worth
the effort to upgrade our Java parser.
Change versions to 1.X-SNAPSHOT / 3.X-SNAPSHOT
Merge branch 'perfCompilation'