Document configuring multiple_frameworks
Add @sorentwo to contributors
Changelog
Update README.md to include Rails 4 installation

As of Rails 4, the :assets group is no longer supported in the Gemfile (http://edgeguides.rubyonrails.org/upgrading_ruby_on_rails.html#upgrading-from-rails-3-2-to-rails-4-0).
Add @panchoqv to contributors
Changelog
Remove reference to rc4 in README

Now that Handlebars has hit a stable release, the README note about which release is packaged in the gem can probably just say "current stable release" instead of a specific version number.
Add @dmarkow to contributors
Changelog
@AlexRiedler takes over as maintainer!
Cleanup order of README and remove files that should not be in the repo.