[java] Add @:keep to Resource.content; it was lost during DCE if only getString and getBytes were used
Add Hashes to stack frames
Merge pull request #2160 from jonasmalacofilho/development

[java] Add @:keep to Resource.content
- do not post process classes that are going to be removed
- allow @:remove metadata to signal that a generic base class should be removed
Merge pull request #2156 from elliott5/development

Modify haxe.Int64.hx to work on php and fix other issues
Use '.' qualified class name in stack debug functions
resolve leftover multi-type abstracts during DCE (closes #2163)
add extractor support (implementation not perfect yet)
store reverse features in m_extra so it can be cached (closes #2159)
handle @:generic inline methods (closes #2158)