added wrapper for ldap compare function
added documentation for `compare` method
Minor tweaks to compare method's docstring.
Merged pull request #4: Expose ldap's compare_s method.
Dropped support for Python 2.5.
Added a test for compare that returns False, refs #4.
Added a not about the authentication method not performing any unbind or re-bind actions, refs #1.
Updated changelog for 0.8 release.