Log Message:
Update ruby-rack12 to 1.2.7.

* January 6th, 2013: Twenty seventh public release 1.2.6
  * Add warnings when users do not provide a session secret
  * Fix parsing performance for unquoted filenames

* January 13th, 2013: Thirty second public release 1.4.4, 1.3.9, 1.2.7, 1.1.5
  * [SEC] Rack::Auth::AbstractRequest no longer symbolizes arbitrary strings
  * Fixed erroneous test case in the 1.3.x series