CLN: cleanup dlers
temporarily skip troubling december
SETTINGS: add start and end dates
API: start api.py
API: quick return if already in renamed form
TST: more tests for dlers
TST: more parer tests
ENH: Add cache checker
API: Change _month_to_dd to use our names
SETTINGS: Change default start to 1995-09
BUG: bad month for sept 1995
BUG: Extend last dd to current
more filtering, fix tests on parsers