Implement APIs added in IDEA 14.1 for Packages view and Coverage view to work.
code review; adapted to IDEA API change (Predicate -> Condition)
refactor for clarity; don't ignore XxxPackage files not related to Kotlin
a bit more cleanup
Merge pull request #541 from JetBrains/rr/yole/coverageView2

Implement APIs added in IDEA 14.1 for Packages view and Coverage view to work