Add code for including one-shot update size in Manvr event
Update docs for new one_shot field
Change one_shot field to disallow NULL values
Change NULL value from 0.0 to -99.0
Improve notes for adding/updating event type
Add docstring note about one_shot
Update version to 0.11
Merge pull request #52 from sot/one-shot

Add code for including one-shot update size in Manvr event