linuxdvb: fix adapter enable/disable

- also remove unused dmx variable in the input thread
Merge remote-tracking branch 'upstream/master' into durationfilter
capmt: fix thread detach bug
Added preliminary HEVC support (no packetizer - only MPEG-TS passthrough)
SATIP: do not show -failed to modify pids- error when no pids are opened
Merge remote-tracking branch 'upstream/master' into durationfilter
webui: Update EPG help files for duration filter et al