Fixes for 239bae7512 (mobile toolbar)

* Use correct class name for setUpToolbar() in MobileViewTarget
* Move shared setUpToolbar() code into ve.init.mw.Target
* Fix iconModuleStyles documentation, remove leading space

Change-Id: Icf5ed36fd817837c0434db8202bef8a78e6cb898
Merge "Fixes for 239bae7512 (mobile toolbar)"