BFM demod fix
The frequency shift was not effective anymore. Fixes issue #78.
CW keyer enhancement
To further reduce clicking and spreading the pulse shaping ramp time is made 20% of the dot length. Thus spreading is made dependent on CW speed which makes sense. Implements issue #76.
Non functional changes
- Removed start threaded sink from device engine
- Further implementation of separate settings object in the channel plugins and partial separation of GUI and core. Now phase 1 is complete.