Missing non-vanilla objects

[dromer]

We don't have to limit ourselves to vanilla. Certain non-vanilla objects could still be ported with relative ease.
Lets list externals and potential objects that could be ported.

ELSE:

• knob - pd still doesn't have a rotary knob, but ELSE provides one. Could simply replace it with [f ] like is done for vsl and hsl. - implemented

Cyclone:

• ==~, !=~, >~, >=~, <~, <=~ - these signal rate logic objects are already implemented in Heavylib, why not bring them to the compiler as well?

Plugdata:

• playhead - this one only makes sense in the DPF generator, but would certainly be doable since we have all the host information available. A simple abstraction with a set of receive objects should do the trick (we already have __hv_dpf_bpm).