Added option to use time of day encoder.

Fixes #16.
@chetan51 Maybe I misunderstood you. I added the two lines above at your suggestion, but I get this error:

```
Error in constructing DateEncoder encoder. Possibly missing some required constructor parameters. Parameters that were provided are: {'name': u'timestamp_timeOfDay', 'w': 51, 'timeOfDay': (21, 9.5), 'n': 2048}
Traceback (most recent call last):
...
TypeError: __init__() got an unexpected keyword argument 'w'
```