fixed attenuation bug
add options to compute_fft
apply calibration values only when returning dbm
VRT capture to file
added a widget witch contains all the device controls
made the layout in the DeviceControlsWidget a property of the class so it can be modified by the user
allow eof on vrt_packet_reader
remove output capture from vrt_packet_reader (wrong place)
removed marker controls from gui_config
fixed y axis not scaling when fstart/fstop/fcenter is changed
fshift will now be set to 0 when using the capture device

Conflicts:
	pyrf/gui/gui_config.py
fixed span changing while time domain mode is activated