Added long date columns to epg view

Hi folks,

epg data for e.g. 14 days ahead sometimes leads to difficulties to schedule the correct entry from the epg grid, since only the weekday is shown. So I added some "longer" formatted column. Maybe this is useful?

Apologies, I'm quite new to both tvheadend and git. :) Just learning... and maybe I'm able to contribut? ;-)

Thanks,
Dietmar.