Completion: minor code corrections after review
Completion: no qualified this for anonymous object + no keyword escaping for qualified this
Completion: escaping of named arguments
Completion: corrected for class nested into class object
Completion: more tests for keyword escaping
KT-4976 Completion ignores smart casts

 #KT-4976 Fixed
 #KT-5718 Fixed
Moved too specific function out of ExpressionTypingUtils (and refactored it)