Enable Topic namespace

Topics now pretend to be inside the NS_TOPIC namespace.  Because they
are only pretending there are several special cases to handle either
by checking if $title->getNamespace() === NS_TOPIC or when
$workflow->getType() === 'topic'.  This was done rather than moving
the workflows to a new namespace/titleText combo to maintain the information
about where a workflow was originaly created, required as part of the
page breadcrumbs. The alternative method of database changes seemed
overbearing.

DONE
* Topic namespace created
* Minor hack to remove skin links on Topic namespace
* Removed duplicated workflow parameter from all topic urls
* introduced Workflow::getOwnerTitle representing page workflow was created at

TODO
* Remove line underneath empty page title

Change-Id: I98d45f053e0892e2b1f3433ce57f8ed084853103
Merge "Enable Topic namespace"