Feature Processing by go code

Two Parts:

1. generate splitting points by called IterEqualHeight method.
2. use splitting points to converse the original features to new combined feature, which could be used in large feature processing when using linear regressiong or classfication

1, generate splitting points

see help info

2, generate new features

given the feature with format value f1:v1 f2:v2 ..., return the split result, with processing:

1. split the feature's value
2. add missing value
3. extend the feature/value to new feature of name feature_value and value 1
4. add bias value

then the result could be used in logistic regression with github.com/xlhector/hector

USAGE

type ./feature_process -help to get usage