Adding dyn-klang and dyn-klank cgens

I've been hankering for dyn-klang & dyn-klank so I've added them as cgens. 

I based the two examples on Supercolliders source: https://github.com/supercollider/supercollider/blob/master/SCClassLibrary/Common/Audio/FSinOsc.sc#L68-L109

I was not sure what should be in: src/overtone/sc/machinery/ugen/metadata/pseudo.clj

Let me know if there is anything I've missed in adding a new cgen.

This should resolve issue #254