[!!!][FEATURE] FormEngine: The extendables

For details, see the ReST files with examples for new API
and TCA changes.

* Split TCA config "type" to "type" and "renderType":
  TCA config "type" is a technical debt since it both defines the
  database storage as well as the widget that is used to render
  a certain field in FormEngine. While "type" is kept, the
  render widget is now extracted to a "renderType".

* t3editor uses this "renderType" now. type=text with
  renderType=t3editor will call the new T3editorElement provided
  by ext:t3editor, and falls back to TextElement if t3editor is
  not loaded.

* t3editor is now enabled for "setup" and "constants" of
  sys_template records if opening the whole record.

* t3editor now works when configured in a flex form.

* Introduce an API in FormEngine NodeFactory to register new
  renderType, used by t3editor.

* Introduce a resolver API in FormEngine NodeFactory to change
  the class that renders a widget or container.

* Split TextElement into TextElement that only renders a textarea
  and RichTextElement provided by ext:rtehtmlarea that renders RTE.
  ext:rtehtmlarea uses the new resolver API to route rendering to
  its own class in case RTE is enabled and configured for a field.

* In TCA section "types" a new array "columnsOverrides" is
  introduced that allows overwriting some column configurations
  of fields. Currently, this works for some View/FormEngine related
  settings like renderType and defaultExtras.

* TCA Migration is introduced to dynamically rewrite TCA before
  it is put into cache.

* TCA migration is called a second time in ext:compatibility6 in
  case TCA is still registered via ext_tables.php. This has performance
  penalty since it is done on every frontend and backend call.

* TCA migration is also called dynamically for flex form definitions.

* TCA migration moves configured t3editor wizards to type=text with
  renderType=t3editor.

* TCA migration removes the 5th parameter "style pointer" from
  types showitem

* TCA migration moves the 4th showitem parameter "extra configuration"
  to "defaultExtras" of "columnsOverrides" of given TCA type.

Change-Id: Ia2c2bc16463a01021c7a6be765b4efa872a130fd
Resolves: #67229
Releases: master
Reviewed-on: http://review.typo3.org/39662


Reviewed-by: Christian Kuhn <lolli@schwarzbu.ch>
Tested-by: Christian Kuhn <lolli@schwarzbu.ch>
Reviewed-by: Frank Nägler <typo3@naegler.net>
Tested-by: Frank Nägler <typo3@naegler.net>
Reviewed-by: Markus Klein <markus.klein@typo3.org>
Tested-by: Markus Klein <markus.klein@typo3.org>
Reviewed-by: Anja Leichsenring <aleichsenring@ab-softlab.de>
Tested-by: Anja Leichsenring <aleichsenring@ab-softlab.de>