changing private _fit to public partial_fit
adding test to rbm
changing partial fit to be seperate from _fit
changing test
saving the random state
making adjustments to variable names and account for sparse matrices
changing xrange to range
changing formatting of documentation
Merge remote-tracking branch 'upstream/master' into rbmbranch
STY Simplify and avoided numpy warnings in imputation
ENH/TST remove unnecessary sorts and complete testing for sparse median
Update plot_svm_regression.py

library imports have been moved to top of the file.
COSMIT Remove unnecessary assertion
BUG: avoid NaNs throwing off class probabilities

In the case where neigh_dist includes at least one zero and self.weights is 'distance',
some values of `weights` may be infinite.
This is ok, except for when normalizing `proba_k`, when it creates NaN values.
fixing warning ignore type
adding test case
conform to pep8
FIX for numpy compatibility, code clarity
MAINT warn of future behaviour change proposed in #2610
changing computation of batch slices to np.array_split