minor fixes
removed _validation import, minor changes to examples
modified the docs to use the pyrf/pyqtgraph library
added decimation controls
added pyqtgraph example
added fshift controls to PyRF GUI
began implementing a configuration methond to the capture device
Merge branch 'capture_device_configuration' into block_mode_speca
Device configurations are only updated when changed, not constantly sending same commands
I data will continue to plot in TD mode in HDR and SH mode
rbw is initialized in all modes to receive 1024 data points
fixed rbw value not changing appropriately
modified examples, fixed fshift text box not using decimals
disabled decimation/fshift box while HDR mode is enabled
fixed bug where spp was not defaulting to 1024
read_data_and_context now supports sweep and stream mode
fixed span not showing properly in block mode
requirements: use pyrf fork of pyqtgraph
fix debian/ubuntu install instructions
CaptureDevice: __init__ backwards compat, device_settings param last