Update yk during initial step size growth stage.

Name fix. Commented out debug prints.
Whitespace
Don't need so much work on dual.
Add eta.

Also fix a couple of simple bugs in weightedModelTypes.
Add eta.

Also fix a couple of simple bugs in weightedModelTypes (this time with weightedModelTypes)
Cython version of projection to simplex.

And a fidelity test for it.
Add matplotlib requirement for plotting.