TST/FIX ensure correct ducktyping for metaestimators
TST extend ducktype testing to handle #2853 case
FIX ducktyping for meta-estimators
TST more rigorous testing of delegation
remove _iff_attr_has_method function
don't give names to decorators
make attribute decriptor have the right docstring.
add regression test for docstring delegation
fix docstrings in sphinx
rename decorator
Fix typos, no shortenings in name, simplify example.
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
MAINT: Remove deprecation warnings in enet_path and lasso_path
Another doc typo fix