Fix MethodAndVariableSnakeCase concerning def and self assignments.

A couple of bugs in regexp matching.
Merge pull request #444 from jonas054/fix_methods_snake_case

Fix MethodAndVariableSnakeCase concerning def and self assignments.
New cop HashMethods
Add auto-correct support for HashMethods
Add auto-correction to Attr cop
Add auto-correction to CollectionMethods cop
Make CollectionMethods aware of collect!
Add auto-correction to SignalException cop
Add auto-correction to EmptyLiteral cop
Add auto-correction to MethodCallParentheses cop
Drop -s/--silent option

Now progress/simple/clang formatters always report summary
and emacs/files formatters no longer report.
Print error summary to stderr to avoid external tools try to parse it
Add auto-correction for DefParentheses
Merge pull request #446 from yujinakayama/drop-silent-option

Drop -s/--silent option