Add option "veryshort" to config.recording.filename_composition

Basically veryshort just starts using name of recorded event and ends using a timestamp.
Without timestamp existing recordings for series/reoccuring events would overwrite eachother.

The Watch - Nachbarn der 3_ Art - 20140716 0927.ts

Config options should be re-worked for config.recording.filename_composition to show filename-pattern instead of the namings veryshort, short, long and standard.