implement readFrontendData method to get a python dictionary containing data

implement readFrontendData method to get a python dictionary containing data
about current used transponder/frontend (frontend state, frontend type, lock
state, sync state, frequency, symbolrate, fec_innter...)
when it is called with True as param it returns the original transponder data
(written to tuner) otherwise it reads the current data out of the frontend
(corrected tuner data)