* prevent too long values for user preferences
* add chart value 0 to y-axis if last value > 0, to always display the zero line (project details)
* add user-preferences to invoice hydrator
* DateTime vs DateTimeInterface
* simplify permission config
* fix query for teamleads limiting to only selected teams not possible
* added team filter in export and invoice search form
* added teams select to timesheet filter
* added team select to report filter
* hide user and team filter if count < 2
