Log Message:
Update ruby-activesupport to 1.4.1.

Changes:
* Optimize Class Inheritable Attributes so that unnecessary hashes are not
  creat ed. [Bruce Perens]
* Added :instance_writer option to #mattr_writer/accessor,
  #cattr_writer/accesso r, and #class_inheritable_writer to skip the creation
  of the instance writer. [ Rick]
* Full test coverage for Inflector.  #7228 [Dan Kubb]