WIP add n_constant_features argument
WIP add constant_features array
ENH avoid splitting on constant features for best splitter
FIX bug with BestSPlitter + ENH avoid searching for a split on constant features
ENH avoid trying to split on constant features for presort best splitter
COSMIT
COSMIT
FIX deallocate memory
FIX proper inititalization
ENH use memcopy instead of while loop
COSMIT
FIX bug with invariant
Simpler swap
ENH: add explanatory coments
pep8
ENH remove unused constant
ENH document and rename EPSILON_FLOAT
DOC improve documentation for the splitting algorihtm
DOC verbose documentation of features and constant_features
Rename EPSILON_FLOAT -> CONSTANT_FEATURE_THRESHOLD + DOC n_drawn_constants & n_found_constant