Unutilized Abstraction false positives

[tushartushar]

We observe some false positives with unutilized abstraction:

1. If a class is used statically, it shouldn't be declared as unutilized
2. If a class or interface is unutilized but has subclasses, then it is not unutilized.

[AntonisGkortzis]

Partially fixed. Many cases are covered by manually resolving methods.

However, more investigation is required in order to fix the cause of the problem (eclipse library fails to automatically resolve the method).