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
Enclosing rules can no longer be references in actions using the `$ruleName` syntax
Fix bugs in argActionParameter

* Allow commas within template arguments of parameter types
* Allow assigning a default value to a parameter
Global attribute scopes are not supported in ANTLR 4
Show arguments, return values, and locals in completion lists
Fix exceptions which appeared during editing tests
Fix numerous problems when working with imported grammars
Build for NetBeans 8.0.1 by default