[FEATURE] Fluid based Module Template

A new class structure around "ModuleTemplate" is introduced to
substitute the rusty "DocumentTemplate". The architecture can
be seen as wrapper around the main html content a backend
controller action creates. ModuleTemplate provides an API
especially for the "doc header" and unifies its display
and creation.

The patch releases single controller actions from fiddling with
doc header details like actual button HTML and hands over
this concern to the framework, so it can steer these parts
at a central place.

Since this API and its embedding in the framework is a rather
complex task that will require further tweaks, this main API
is mostly marked as "experimental" for now: It will further
settle with 8. For extension authors it means that *if* this
API is used, there may be code adaptions required in version 8
since parts of the API will be adapted to further needs.

Resolves: #69814
Releases: master
Change-Id: I81cb9f01ebc4b13d8d88a928811e563d83ec97cd
Reviewed-on: http://review.typo3.org/43465


Reviewed-by: Benjamin Kott <info@bk2k.info>
Tested-by: Benjamin Kott <info@bk2k.info>
Reviewed-by: Christian Kuhn <lolli@schwarzbu.ch>
Tested-by: Christian Kuhn <lolli@schwarzbu.ch>
Reviewed-by: Mathias Schreiber <mathias.schreiber@wmdb.de>
Tested-by: Mathias Schreiber <mathias.schreiber@wmdb.de>