Log Message:
Update ruby-activeldap pacakge to 3.1.1.

3.1.1: 2011-11-03

* Supported Rails 3.1.1.
* [GitHub:#9] Fixed a typo in document. [warden]
* [GitHub:#11] Added persisted?. [bklier]
* [GitHub:#16] Supported 4 or more bytes salt for SSHA and SMD5. [Alex Tomlins]

  Thanks

   * warden
   * bklier
   * Alex Tomlins

3.1.0: 2011-07-09

* Supported Rails 3.1.0.rc4. [Ryan Tandy, Narihiro Nakamura, Hidetoshi Yoshimoto]
* Removed ActiveRecord dependency and added ActiveModel dependency.
* Used YARD instead of RDoc as documentation sysytem.