Added basic data model for events.
Added first version of data model for events.
A minor tweak to the data model.
A few changes to the event data model:
	- added a main image for the event, to be stored as a URL.
	- cleaned up the responses, responses can be a comment an image.
	- added location information to the event.
Added logic test target for building data models.
Added source files for event models.
Added creation date to event responses.
Added test for building an saving a PSlocation.
Tweaked the data model a bit:
	- fixed up some required properties.
Added basic tests for building individual models.
More tweaks to models.
Added OCMock for other tests.
Some minor clean up.
Merge pull request #13 from mdewolfe/FEATURE_models

Feature models with Unit Tests