Add a new command that lets you wait for an attribute to appear in
a value. Using this you can do things like wait for a managed entry
to be created, adding a new objectclass to the parent entry.
This is controlled by a new booleon option, wait_for_attr, defaulting
to False.
https://fedorahosted.org/freeipa/ticket/1144
https://fedorahosted.org/freeipa/ticket/1259
Python code will see nsaccountlock as bool. JavaScript code will also see it as bool.
This allows native boolean operations with the lock field. Passes both CLI and WebUI tests.
