proc_put, proc_get and proc_get_hex are used in many files.
Avoid duplication by moving them to common/proc_tools.c.
Convert azbox's cVideo to use proc_tools.h
TODO: some code is very similar to SPARK (record and pwrmngr
are just symlinked, dmx is almost identical). Reduce duplication
by factoring out DVBAPI code into an extra directory.
* what works: audio, video, demux
* what probably doesn't work or is untested: record
* what very likely doesn't work: playback
Playback is just copied over from aztrino and made to compile.
If you are lucky, it just segfaults :-)
