Add support for SoX effects

[igece]

Effects pending to be implemented:

band, bend, biquad, channels, chorus, compand, dcshift, deemph, delay, dither, downsample, earwax, echo, echos, equalizer, fade, fir, flanger, gain, hilbert, ladspa, mcompand, norm, opps, overdrive, pad, phaser, pitch, rate, remix, repeat, reverb, riaa, silence, since, spectrogram, splice, stat, stats, swap, stretch, synth, upsample, vad

[harmandeepsinghkalsi]

@igece ,could you please confirm if the effects above mentioned are implemented yet or not?

[igece]

@harmandeepsinghkalsi as title says, the effects in the list are not yet implemented.