ENH: support float value for max_features
DOC: if float, then max_features is a percentage
ENH: Defer parameter checking of trees
DOC: GBRT max_features
TEST: added test
ENH: use numbers
FIX: numpy integers
ENH CountVectorizer using arrays instead of lists
BUG restore empty vocabulary exc in CountVectorizer
ENH prevent copying of indices in CountVectorizer

... and values as well, if possible.
DOC credit @ephes
Merge pull request #1713 from larsmans/vectorizer-memory-use

ENH CounterVectorizer using arrays instead of lists
FIX MinMaxScaler bug.
COSMIT use callable instead of hasattr
Merge pull request #1727 from amueller/min_max_scaler_fix

FIX MinMaxScaler bug
FIX : fix kfold balance due to int rounding
FIX : test due to KFold change
FIX : better fix of KFold balance
fix doctest
Removed an unnecessary if statement in KFold __iter__ method.