make month table min-height: 90px to remove jumpy switching
add booking block destroyed check
fix several small corner cases in timecard month graph
change everything to use dateranges

Conflicts:
	phprojekt/application/Timecard/Controllers/IndexController.php
	phprojekt/htdocs/phpr/Statistics/WorktimeMonthGraph.js
	phprojekt/htdocs/phpr/Statistics/WorktimeMonthTable.js
	phprojekt/htdocs/phpr/models/Timecard.js
enhance datetextbox to support special values

we now support the values 'lastOfMonth' and 'firstOfMonth'
use datetextbox special values in statistics view

Conflicts:
	phprojekt/htdocs/phpr/template/statisticsView.html
add a function to schedule the month widget update

that way we can collect all the 'update' callbacks on startup
and still just send out one request
update month widgets on time range change
add attach point for start end date
fix unexpected behavior when selecting end date

the user does not expect the end date to be exclusive
Clear the session on setup start

The migration stores some values in the session, which causes a failed migration
to start from the point where it failed after a cleaned database. This can only
be fixed by clearing the session.
Rename projects with the same name under the same parent in migrations

We enforce unique project names under the same parent project since a few
versions via a database constraint.
fix the deletion handling and structure
stop migrating todos
stop migrating nodes
stop migrating filemanager entries
stop migrating contacts
stop migrating helpdesk entries
Stop migrating calendars

We just keep the module because we need some of the code, we don't really
provide a calendar any more.
Remove jsonMonthList

jsonMonthList is only used by the deactived and unused legacy
Timecard and therefore not needed anymore.