Update to ANTLR 4.4
Support Python 2 and Python 3 code generation
Remove unreachable ambiguous alternative
Allow set elements to have element options
Allow elementOptions to appear in more places

* Alternatives
* Rule references
* Embedded actions
* Semantic predicates
Use diamond operator where appropriate
Show lexer modes in completion lists
Use distinct images for fragment and token lexer rules
Add support for custom channel declarations
Remove references to modules not included with NetBeans Java SE edition