2 New attributes and bug fix

Added atkCKEditorAttribute and atkDateTime2Attribute
Fixed bug Fixed bug in checkTabRights (bugzilla.achievo.org 1708)
Add CLEAR buttom to admin/list page

Activate with $config_clear_search = true;
Clears all search values and resets dropdown search values
Additions to security log

Added listener to atksecuritymanager to optionally log login fails,
logins/logouts and node actions performed
Fixed typo in atksessionmanager
Configurable security listeners

Security listeners registered in atksecuritymanager now configurable via
optional $config_security_listeners
Default is atksecuritylistener
Merge pull request #11 from wayneh/develop

2 New attributes and bug fix