some overrides
extra code
IDEA-123484 initial. lexer, parser and psi for traits
IDEA-123484 modifier inferring for trait members
IDEA-123484 highlighting for extends list of traits, inc/dec on trait field
IDEA-123484 anonymous from traits are not allowed
cleanup
IDEA-123484 trait fields and properties
IDEA-123484 abstract modifier for trait methods, some code duplicates removed
closure recursion test