Swaps all docHeader rows for the backend modules.

Function menu and CSH are moved to the top row while
buttons (save, close and shortcut) are moved underneath.

Also includes a compatibility layer for non-core legacy
extensions that don't include expected template structure.
These non-standard docHeaders are reformated by CSS.
To deliver fall-back logic the HTML structure was redefined.

Change-Id: I345646b053a1587b0f82a9bde43b479b8ca4767e
Resolves: #38759
Resolves: #33508
Releases: 6.0
Reviewed-on: http://review.typo3.org/12788
Reviewed-by: Max Roesch
Reviewed-by: Wouter Wolters
Tested-by: Wouter Wolters
Reviewed-by: Christian Kuhn
Tested-by: Christian Kuhn