Remove debugger gem integration from RubyMine

Debugger clashes with ruby-debug* gems in RubyMine. See below links for good references regarding this issue:
[1]: http://stackoverflow.com/questions/11672201/unable-to-debug-in-rubymine-4-5-using-ruby-1-9-3
[2]: http://stackoverflow.com/questions/1083451/debugging-in-ruby-1-9/10414984#10414984
[3]: http://stackoverflow.com/questions/10323119/cannot-load-such-file-script-rails-getting-this-error-while-remote-debuggin/10325110#10325110
[4]: http://youtrack.jetbrains.com/issue/RUBY-11800#comment=27-417333

If you're facing issues in RubyMine. Just follow link 3 mentioned here. Try installing just one gem in RubyMine and RubyMine will prompt you for necessary debug gem installations.