Eq rack2

This is an updated version on Nicus EQ Rack Branch.
It enables the full power of the effect back-end for the EQ Knobs as well.

You can select which EQ should work on which deck and you can load any other effect to the EQ Slots.

Next steps to merge:
* Add a second Effect slot, to utilize the Filter knob / fourth band, some Controllers offer.
* Add an effect chain to preferences for master EQ 

  
Ok -- maybe we can change it to a bitvector of "traits" an effect has at some point. For plugin effects you mentioned user effects wouldn't have this bit -- maybe they could manually set the traits for their effect via the plugin preferences GUI (once we have one).