Update compressor and crossover documentation and add examples

[chadrockey]

I wanted to ask you if this was valid syntax for setting all of the parameters of the compressor at once.

I figured while I was asking, I might as well update the documentation and add some examples.

[mrene]

Almost! -b is for bypass so you'd want -b off to have it part of the signal path

[chadrockey]

@mrene Updated! I am always bugged when there's negatives in enable/disable flags... So difficult to keep "bypass - negative, off - negative, therefore on" straight.

I also took this opportunity to add a few examples of the xover. Is the xover similar to the UI where if you load the filters but do not turn off the bypass, then they won't apply? I added the bypass commands into the examples since I think most people would forget that without the UI showing the greyed out options. Would you want to add convenience to the crossover import that automatically turns bypass off? I don't think too many people would be loading filters they do not intend to use.

[mrene]

Both PEQ and Crossovers automatically unbypass the imported PEQ and Crossover Groups if you use the import subcommand. If you use coefficients then the bypass status is not modified. You wouldn't necessarily want to set bypass off for all groups if you only imported the first one so I wouldn't advise doing a bypass all after changing values.

[chadrockey]

@mrene Comments addressed.

[mrene]

Thanks!