* One of the main reasons behind mutant was to get a rid of rspec-1.3
in my toolchain.
* Remove most of mri specific stuff from Gemfile.
* Remove of mri specific taks will happen later, will heckle locally
with external rspec-1.3 + heckle setup.
* Mutant should be self hosting as fast as possible :P
* This infrastructure, especially the rake tasks should be
gemified at some point in the future. I copied exactly the same
bytes many times in the last month.