ts_todo.txt

- DatetimeIndex.union empty -> error
- DateOffset display sucks -> 1 Day

gp- get rid of Ts class, simplify timestamp creation
- rename tzinfo to tz
- get rid of deprecated / new offset mapping, will deal with users
- add Index.is_unique, check via is_monotonic cython routine
- tofreq -> asfreq again
- work around numpy refcount bug in Index.append with datetime64 type promotion
- fix bug in Index.join with empty indexes
- handle legacy DateRange unpickling in BlockManager
- date_range/bdate_range factory functions, test refactoring
- got rid of all deprecation warnings in test suite, usages of DateRange
- fix merge issue? in generate_code.py
- attach tz in DatetimeIndex.asobject
- failing duplicate timestamp test
- _tseries.pyd depends on datetime.pyx


- BUG: time_rule DateRange tests