Release Name: 2.5.7

Notes:



Changes:
* Clean the cached git repository
* Fixes perforce issues reported at http://bit.ly/wt0es
* Improved back-tick handling code in relation to the above.
* Removes rails-assumptions, more info see a freshly generated config/deploy.rb
* Fixes a Git issue when submodules update upstream.
* Capify now creates the config directory in directories without one.