Add header for related tag in tag-browser.
Fix minor bug in tag-loading.
Merge branch 'master' of https://github.com/opfo/app

* 'master' of https://github.com/opfo/app:
  Deleted some code that wasn't used
  Change NSLog to DLog.
  Remove NSLog call.
  Fix crash when OPFQuestionsViewController was deallocated.
  Fix multiple references to the same file in Xcode.
  Fix laying out question metadata header view subviews.
  An user which is not logged in cannotpost questions, answers or comments anymore