Hygiene: Push page creation to DeferredUpdates

In a followup patch to this I add tests to run the flow API
directly, one issue that was run into is that the doEditPage call
within the controller starts and ends a transaction, but we are
currently within the flow transaction and don't want that closed
yet.  As such push the update into the deferred updates, using
the queue so it only happens when the commit succedes.

Additionally this call to the occupation controller is responsible
for 15-20% of the runtime of a new-topic action. This wont likely
help API consumers, i believe the xhr code is waiting for the request
to complete, but browsers submitting the form directly should get
their response on screen faster.

Change-Id: I9bad5d2def0f58bc9cc1751a648ee54bfbcbf4c1
Merge "Hygiene: Push page creation to DeferredUpdates"