Cwc/Capmt changes

Some changes are cleanups for the descramler.

A support for the TCP mode was added to the capmt client (mode 3). Also, another mode 4 was introduced (for the camd.socket) - required patches oscam with http://www.streamboard.tv/oscam/ticket/3753 . I think that I fixed also some errors for mode 2. The capmt code requires more updates:

- better filter code for mode 3 and 4 (oscam asks for PID 1 which is not transferred to oscam at the moment)
- use non-blocking I/O and queued writes to not block the other mpegts processing

Other parts of descrambler should be also improved:

- move the descrambler instance selection one level up (descrambler.c)
- probably a better pid handling
@perexg shouldn't it be pc-nodmx here?