* calf-updates:
+ DSP primitives: fix a rather stupid bug in clamping functions
+ Monosynth: fix type bug that made it impossible to compile with g++ 4.2
+ AutoHell: update AUTHORS file
+ GUI, Multiband Compressor, Toggle button: apply more fixes and additions by Markus Schmidt
+ Multiband Compressor: better metadata
+ Multiband Compressor: new module (first version, by Markus Schmidt, based on code by me and Thor) plus associated refactoring and graph colour scheme update
(cherry picked from commit 65f6bb7135)