build: ensure git submodule with dvb-scan data is updated.
build: remove use of submodule for dvb-scan data

Revert back to manually fetching, though now its a git report its somewhat
simpler and we'll avoid using a separate script.
build: correction to ensure old data is removed.
timeshift: fix start of buffer bug and add some useful debug.
timeshift: fix printing error.
libav: detect versions that are to old for libav muxing
Update dvb_satconf struct to support rotor type and position. Add rotor type and position to webui in Satellite config tab.
Merge branch 'rotor-support' of github.com:jsm174/tvheadend into rotor-support