ENH vectorize DBSCAN implementation
ENH sparse support in DBSCAN
ENH support weighted samples in DBSCAN
FIX DBSCAN.fit_predict now also supports sample_weight
DOC/COSMIT clean up according to review
Merge pull request #3994 from jnothman/vec_dbscan

[MRG+1] DBSCAN: faster, weighted samples, and sparse input
TST add tests for nd grid-search can train_test_split
MAINT dev version to follow PEP440
FIX correct name due to rebase error
Spelling in heading newgroups -> newsgroups

The section title is "newgroups", this fixes it so that it matches the rest of the document.
Merge pull request #4003 from ClashTheBunny/patch-1

DOC Spelling in heading newgroups -> newsgroups
FIX: Bug in sparse coordinate solver in lazy centering
Merge pull request #4010 from MechCoder/sparse_bug

[MRG] FIX: Bug in sparse coordinate solver in lazy centering
Another doc typo fix
Merge pull request #4012 from pricingassistant/doc-typo-fix

Small doc typo fix in Model evaluation