Revision 159609

Port Improved ValidWhen Exception Handling to 1.2.X Branch

Improve ValidWhen Exception Handling - exceptions are now logged and validation fails returning an error message with details of the error.

The problem with ValidWhen is that currently if there is an exception processing the 'test' expression from the validation.xml  then it just prints a stack trace and returns 'false'. However returning 'false' doesn't cause the validation to fail - for validation to fail and error message also needs to be added. This causes alot of confusion for users, since if they mess up the 'test' expression, then validation passes! This change rectifys that.