Java to Kotlin conversion: minor refactorings after code review
Java to Kotlin converter: no more 2 conversion modes for each test, just a few tests to test non-standard settings
Java to Kotlin conversion: minor
Java to Kotlin conversion: fixed a few bugs related to modifiers

 #KT-4424 Fixed
Java to Kotlin converter: refactoring work with modifiers, dropped Modifier.FINAL
Java to Kotlin converter: fixed overriding of Object methods
KT-4418 Converter from java should honor "@Nullable" annotations

 #KT-4418 Fixed
Java to Kotlin converter: more smartness about variables nullability
Java to Kotlin converter: even more smartness about nullability
Java to Kotlin converter: and even more smartness about nullability

 #KT-5162 Fixed
Java to Kotlin converter: converting usages of Kotlin properties from Java
Java to Kotlin converter: converting usages of Kotlin global and extension functions and properties
Java to Kotlin converter: converting usages of Kotlin class object members
Java to Kotlin converter: converting usages of Kotlin object members

 #KT-5172 Fixed
Java to Kotlin converter: code refactoring - extracted some code from Converter into TypeConverter
Java to Kotlin converter: replacing equals call to ==/!= and no redundant parethesis generation

 #KT-4426 Fixed
Java to Kotlin converter: refactored code to drop ArrayInitializerExpression
Java to Kotlin converter: minor corrections after code review
Java to Kotlin converter: more smartness about nullability
Java to Kotlin converter: correct code generated for accessing nullable variables