Deprecated framework rake tasks should exit with non-zero exit code

The rails:freeze:gems, rails:freeze:edge, and rails:unfreeze tasks have been deprecated in Rails 3.0.0 in favor of Bundler. When executing any of these tasks, they currently output a deprecation message via puts. However, this won't halt the rake execution chain and it doesn't return a non-zero error exit code to the OS level. This means any automated use of these rake tasks will fail silently with only a message that a human must read to notice that they didn't execute properly.

This patch changes the puts to abort so that the rake execution chain is halted and the OS receives an exit code of 1.