backout r11644.

revert Rails version to 3.2.12.

git-svn-id: svn+ssh://rubyforge.org/var/svn/redmine/trunk@11647 e93f8b46-1217-0410-a6f0-8f06a7374b81
upgrade mocha ~> 0.13.3

git-svn-id: svn+ssh://rubyforge.org/var/svn/redmine/trunk@11648 e93f8b46-1217-0410-a6f0-8f06a7374b81