The vendor was renamed from `wrm` to `werkraummedia`.
And the namespace vendor was renamed from `Wrm` to `WerkraumMedia`.
That way all references to PHP classes as well as the package name
itself need to be adjusted.
Properly cleanup system.
Delete further records when deleting everything.
Also respect further records when purging old entries.
Respect:
* sys_category_record_mm
* sys_file_reference
* sys_file_metadata
It will search for all dates within the past and remove them. Afterwards
all events with no dates are searched and removed.
As DataHandler is used for deletion of events, there is already logging
within TYPO3, as well as recursive deletion for sys_file_references.
To speedup for large data sets, deletion of dates is done without
DataHandler.
