Merge pull request #115 from hawesie/hydro-release

Added sanity checking to task routine.
updated changelogs
0.0.15
Use `is None` instead of `not`.

There's a reason it has been invented. This (and my next PR) probably fix the "local timezone doesn't work anymore" thing.
Merge pull request #117 from lucasb-eyer/hydro-release

Use `is None` instead of `not`.
More none checking changes.