Add static data handling
Add package data
Change filter to return events partially contained in start/stop

Previously event filter(start, stop) returned events that were
fully contained within start : stop.  Now it returns events
that are partially contained within the interval.  I.e. events
that event partially intersect start / stop are returned.  In this
way something like the following gives a useful result::

   events.dwells.filter('2012:002:00:00:00', '2012:002:00:00:01')
Merge pull request #15 from sot/change-filter

Change filter to return events partially contained in start/stop