Fix some style problems
Remove rbx specific gems in gemfile these do not fix the singleton problem
Remove detection of special case via backreferences

This is IMHO the most invasive implementation for 1.9 style hash symbol key syntax.
Emit non empty hash with whitespaces before and after curly braces
Merge master into hash_formatting

Conflicts:
	lib/unparser/emitter/literal/composed.rb
	lib/unparser/emitter/literal/primitive.rb