* Resolved an issue with the ESP8266 where gamma correction would be
performed twice. Changed GAMMA_CORRECTION to SOFTWARE_GAMMA_CORRECTION
to make a distinction between software and firmware gamma correction.
The ESP8266 does firmware gamma correction and dithering, while the
Raspberry Pi uses slightly more inferior software gamma correction.
Changed the software gamma table to match the gamma table used in the
ESP8266 firmware.
* Improved the spectrum visualization by using one of the color channels
to visualize the absolute value of the temporal derivative of the
spectrum. Also added a feature to reject the "common mode" spectral
components, which is analogous to the spectral DC component.
* Signficantly improved the GUI and added a frequency adjustment slider.
Adjusting the frequency range has a big impact on the visualization
output. Recommend using a high frequency range (something like 4 kHz -
10 kHz) when running the scrol visualization.
* Moved all module settings to a new config.py file
* Completely overhauled visualize.py and added a new radiate effect that
colours the radiative beats according the beat frequency.
* Improved some constants like the decay constant to be parametric so
that they scale to any led strip size
* Added temporal dithering to Beat.update_pixels() so that it now
supports fractional speed values. Being limited to integral values was
starting to become a problem.
* Overhauled and simplified the LED module.
* When updating pixels, the LED module no longer sends UDP packets for
pixels that have not changed. This optimization reduces the packet load
significantly and should allow for higher refresh rates.
* Renamed lookup_table.npy to gamm_table.npy to better reflect that the
table is used for gamma correction of the LED strip
