adding gemspec
removing unused files
removing legacy rails support, updating generators, locking gem at ruby version 1.8.7 because tests blew up at 2.0 (minitest/mocha incompatibility)
adding Gemfile
updating readme
adding lib/mail-fetcher.rb to make inclusion easier (no :require required in gemfile)
removing another obsolete file -- related to 3a74624
depending on system_timer only if RUBY_VERSION < 1.9
added support for Imap scopes as an arg