[TASK] Cast log message to string

PSR-3 expects loggers to accept objects as log message and to
cast them to string.

Resolves: #48877
Releases: 6.2
Change-Id: I7558b6db675704d67048914b79a7d8e405bc55d0
Reviewed-on: https://review.typo3.org/21804
Reviewed-by: Christian Kuhn
Tested-by: Christian Kuhn
Reviewed-by: Wouter Wolters
Tested-by: Wouter Wolters
[TASK] Docheader drop-shadow

Crisps up sections by removing Docheader drop shadow.
Improves hierarchy: Strips docheader from module menu.

Change-Id: I96ceaa4c2080740a77704c57a453165debf1d036
Resolves: #49597
Releases: 6.2
Reviewed-on: https://review.typo3.org/21808
Reviewed-by: Christian Kuhn
Tested-by: Christian Kuhn
Reviewed-by: Wouter Wolters
Tested-by: Wouter Wolters
[TASK] Remove not needed table in permission legend

Resolves: #49599
Releases: 6.2
Change-Id: Ied101a590c9fa99c7f2ec1c75a9a646e0f4cfc81
Reviewed-on: https://review.typo3.org/21807
Reviewed-by: Christian Kuhn
Tested-by: Christian Kuhn
Reviewed-by: Wouter Wolters
Tested-by: Wouter Wolters