DOC: some documentation for the Tree Cython structure
DOC copyedit RBM docstrings

Removed the fake LaTeX; it wasn't showing up on the website
and it looks bad in IPython.
Merge pull request #2216 from glouppe/tree-doc

[MRG] Additional documentation for the Tree cython structure.
Rename LabelBinarizer.multilabel to .multilabel_ + DOC
WIP: partial fit for discrete naive Bayes models
Remove the class_prior partial_fit param
WIP: started to factorized the raw count collection
Incrementally is useless now
Add reference to the Manning text + restaure previous smoothing
FIX shape issue when y has only one single class + some missing doc
Factorize common classes checks in partial_fit implementations
Add note on a possible future performance optimization
Add a note on performance tradeoffs in the docstring of partial_fit
More informative error message. Also CV now use integer indices by default now.
Use floats everywhere to get rid of warnings when using sample_weight
More input checks
Better test name
Remove redundant shape check already done by check_arrays
Add missing test for sample weight with partial_fit + fix issue classes passed as a list instead of an array
One more input check test