Remove binstubs from git.

Think I'm going to come down on the other side of dhh on this one:
https://github.com/rails/rails/commit/61b91c4c55bcbd5a2ec85d6e1c67755150653dff

Having bin/rails present was making it difficult to use the console on remote
servers due to their lack of spring and rvm.
Convert & test mailer actions to new rails methods
Convert and test remaining cloud-crowd jobs