Add 'closure' as option to Enum Obfuscation

Closure mode for Enum Obfuscation allows replacement
of the Enum's name to be done via the Closure Compiler
instead of GWT.

See here: http://goo.gl/VQptuu

The benefits of doing so are that Closure supports
a deobfuscation for such mapped strings which currently
isn't encoded in SourceMaps yet.

Change-Id: I8e15d48391f5c31c016a7bbbe3ce988aec80a586
4 files changed