Build Sanity

This PR serves to greatly simplify the installation/development process YOWL. Features added include adding `Rakefile` compatibility for Ruby 1.9.2+, a bash script to install libraptor1 from source on OS X machines, a .gemspec file so that developers can use the standard RubyGems workflow to build/install/push, and documentation that's more informative and less development-environment-agnostic documentation.