Incremental java compilation, started adding coverage for cross-task incremental java compilation. Made some small fixes on the way. Flushed out some missing capabilities.
Enabled one of the tests.
Made the test more readable.
Fixed one of the problems with incremental java compilation wrt jar change detection. On the way to fix the current jar change model.
Added few more integ tests to incremental java compilation feature.
Started satisfying one more case (incremental java compilation, jar changes).