Minor fixes

• fix missing values in .predweights, which now contains csv of value/weight pairs (issue #3)
• fix botched error regression training when we got samples not in an OOB (issue #6)

First release

First release, with small fix for model choice.

• OOB confusion matrix was computed on training set and not on OOB samples, fixed.
• Subboostraping is now enforced everywhere at 10^5