adjust distortion scaling

improve algorithm

Change offset for a better asymmetry control, that changes the shape of
the input signal by setting the amount of distortion for the negative
values without affecting the positive values.

Calculate post gain using RMS like with polynomial drive.

update README

lv2-examples are now pd

improve offset processing

remove -std=gnu99 flag

fix Makefile targets

Add the source

simplify processing

This commit removes the internal filters and leaves just a simple DC
blocking filter.

remove octave files

add the rest of controls

fix lpf filter * to -

refactor controls

Rename Input Gain to Gain and Output Gain to Gain.

add resonance and presence filters

add tone shaping filters

This begins the work on making this plugin a more of a general
`amp-in-a-box` type of plugin. There are eight filters in total
implemented as biquad IIR filters.

Bright is a high shelf to smooth the normal response of passive guitar
pickups.

Tight is a high pass filter to cut out low frequencies.

Bass, mids, treble are peaking eqs to be used with 'on board' controls.

Cab filters are low and high pass filters to mimic the response of a
cab.

format

remove guix.scm

add octave implementation for biquad

update README

update TODO

fix on off switch text being off center