[TASK] Allow sys_category in rootpage

Allow sys_category records to be stored in the rootpage. (pid=0)

Resolves: #47530
Releases: 6.2, 6.1, 6.0
Change-Id: Ie71a13ec9a1be65c57e28fff63f003fc5caa6ac1
Reviewed-on: https://review.typo3.org/21338
Reviewed-by: Georg Ringer
Tested-by: Georg Ringer
[BUGFIX] Page title change directly updates title in content area

Updating the page title in the page tree by double click editing it
calls the changes in right order, by first persisting the
change and then doing the reload of the content area.

Resolves: #49706
Releases: 6.2, 6.1, 6.0
Change-Id: Id108659f1a8bd7a4ecd003337b0782d4fe7d3b68
Reviewed-on: https://review.typo3.org/22191
Reviewed-by: Georg Ringer
Tested-by: Georg Ringer