validationFailedWithException

CCDatePicker was not "bubbling up" errors making it impossible to catch them on the page. Ripped off the validation code from AjaxDatePicker verbatim and applied it here. Works well.

Signed-off-by: Aaron Rosenzweig <aaron@chatnbike.com>
Change the time zone example from a hard coded string to the default timezone to match EREditDatePopupOrNull
Merge pull request #400 from recurve/CCDatePicker_validation

validationFailedWithException
Merge pull request #401 from daveeed/pull_request

Hardcoded timezone example => Default time zone
Fix ERXEOAccessUtilities createRelationship method. isClassProperty of
true creates two relationships. False doesn't remove an existing one.
Updating method to check the class properties explicitly and add/remove
relationships as required.
add generics
add some helper methods converting a set to a sorted array
NSMutableSet.addObjects needs to clear cache