greater commit than expected. informations from tank now stored into database; introduced a new switch "--recreate-database"

reactivated fallback and callback from lqs, fixed multiple lineins on engine level, having the problem that fallback does not start

got too many data from pv. data is now filtered => easier debugging. now it is only possible to comment this to disable this function

enabled API call for liquidsoap state (enabled & connected streams, enabled & recording recorder, enabled lineins and enabled lineouts)

This reverts commit 62a8c7ba, reversing
changes made to a9c94736.

started to implement trackservice. removed unused (comba)methods from scheduler.py&calender.py. minor beautyness improvements