cp.py _init has off-by-one error

Specifically, line 198 and 201 seem to consider too small ranges when initialising, leaving Uinit[0] with null values.

I didn't look into why this seems to work when using default settings. But it did crash my custom code using another matrix factorization method, leading me to believe that Uinit[0] really is meant to be initialized?

I.e. should be "for n in range(0, N)"
