Roll back scoring to 1-based classes

Scoring is back to an array of floats:
float[0] = holds the prediction, or result for regression.
float[1..N] = holds the class distribution for N classes
Bunch of places pick up a +1 (or not).
Scoring a GLM2 returns a class distribution along with the prediction
All Models should now always report a class-distro
Merge branch 'master' of github.com:0xdata/h2o