DOC: provide an axis alises example in the cookbook.rst
DOC: update RELEASE.rst
BUG: fixed issues where passing an axis of 'index' would fail (as its expecting an axis number)
CLN: change to_csv 'legacy' keyword to engine=='python', consistent with c_parser
Merge pull request #3110 from jreback/aliases

BUG: GH3109 fixed issues where passing an axis of 'columns' would fail
Merge pull request #3177 from jreback/alias_cook

DOC: provide an axis alises example in the cookbook.rst