Autolayout related memory leaks

[ehren]

The heap profiler shows this allocation stack associated with a large number of leaks:

^^ above shows session with heap snapshots taken on the main menu of the WOCCatalog app (snapshot taken every time a view controller is loaded and unloaded; WOCCatalog needs patch from #1462). There's about a 400KB leak, not entirely autolayout related; leak is worse without fix in #1461.

[jaredhms]

Thanks for finding this and for tracking down the root cause.