Support to Ruby 1.8.7

Converted ntlm.rb to unix format.

Removed Gemfile.lock from git, explanation at http://yehudakatz.com/2010/12/16/clarifying-the-roles-of-the-gemspec-and-gemfile.

Based on https://github.com/WinRb/rubyntlm/commit/3f54039a57f88b8ab8fc68dbbbd10af9d1ad2df5 commit, extracted EncodeUtil to define method, based on Ruby version.

I'm not sure if what i did on line https://github.com/rogerleite/rubyntlm/compare/WinRb:master...support_to_ruby18#L4R41 is correct. Suggestions are welcome.