Merge pull request #5995 from jreback/timedelta_fixes

BUG/CLN: clarified timedelta inferences
DOC: make zipped HTML docs available GH1876
Merge pull request #6020 from y-p/PR_GH1876

DOC: make zipped HTML docs available GH1876
DOC: update mailing list
TST: remove test.py (accidently added)
PERF: DataFrame.apply perf enhancements & added vbenches (GH6013)