[Customize] add preferred tuner option. [DH] data/setup.xml [DH] lib/dvb/db.cpp [DH] lib/dvb/dvb.cpp [DH] lib/dvb/dvb.h [DH] lib/dvb/frontend.cpp [DH] lib/dvb/frontend.h [DH] lib/python/Components/UsageConfig.py [DH] lib/python/enigma_python.i...