[DOC] Remove that RBM's are not implemented yet
Merge pull request #2361 from rolisz/patch-1

[DOC] Remove that RBM's are not implemented yet
COSMIT refactor Hungarian algorithm
DOC while we're at it, link to our own RBM docs
FIX: release reference to X in _tree.splitter
Merge pull request #2363 from glouppe/tree-memory

FIX: release reference to X in _tree.splitter
DOC: fix metrics documentation format

Fixes #2306.
FIX+TST non-consecutive or duplicate vocabulary indices

* added extra checks for custom vocab in CountVectorizer
* added test for custom vocab to check fauly vocabs

Fixes #2357.
Better docstring for KMeans.predict.
Move estimate_bandwidth test to its own function.
Add predict method to MeanShift.
Add predict method to AffinityPropagation.
Add missing docstrings to test functions.
Add what's new item.
Remove warning in AffinityPropagation.
Fix grid search test.
More user-friendly error message.
COSMIT: change variable name.
DOC adding description for handling of the auto parameter in neighbors
Added cosine distance metric for sparse matrices

- Added 'cosine_distances' function to sklearn.metrics.pairwise.
- Added 'cosine' as metric in 'pairwise_distances' function.
- Corrected doc string of same function, because all metrics based on
the 'manhattan_distances' function (i.e. 'cityblock', 'l1', and
'manhattan') do currently NOT support sparse matrices.
- Added corresponding corresponding unit test.