Log Message:
Update ruby-rack13 to 1.3.9.

* January 6th, 2013: Twenty eighth public release 1.3.7
  * Add warnings when users do not provide a session secret
  * Fix parsing performance for unquoted filenames
  * Updated URI backports
  * Fix URI backport version matching, and silence constant warnings
  * Correct parameter parsing with empty values
  * Correct rackup '-I' flag, to allow multiple uses
  * Correct rackup pidfile handling
  * Report rackup line numbers correctly
  * Fix request loops caused by non-stale nonces with time limits
  * Fix reloader on Windows
  * Prevent infinite recursions from Response#to_ary
  * Various middleware better conforms to the body close specification
  * Updated language for the body close specification
  * Additional notes regarding ECMA escape compatibility issues
  * Fix the parsing of multiple ranges in range headers

* January 7th, 2013: Thirtieth public release 1.3.8
  * Security: Prevent unbounded reads in large multipart boundaries

* 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