General compressor improvements:
- pulled gain apart for monitoring and multichannel support
- improved readability
- improved makeup-gain calculations
- added block processing

Renamed some more faust internals and removed an unnecessary variable, with the added bonus of improving inlining as well when looking at the assembly.

Reduced the cost of parameter changes by only recalculating the affected internals, inlined all calculations to reduce method calls.

Fixed recalculating release on SetRelease and resetting makeup gain when disabling auto makeup

Some additional documentation (unfinished)

Added fast pow10f and approximations for log2f and log10f

Cleaning up some documentation, added getters for the parameters (for monitoring the state of the compressor, when desired), using the faster pow10f and log10f from my additions to dsp.h

inline directive in class definition is superfluous