Don't return null points in GeoJSON

Avoid null values in GeoJSON - Leaflet throws errors on these.
They shouldn't make it into the DB, but best to be fault tolerant
General UI Fixes

Tweaked small things here and there

added .sass-cache to .gitignore
Add media schema
Add rules and validate of media data
Add ability to fetch all media and media by id:w
Add test cases for media model
Merge branch 'master' of https://github.com/ushahidi/Lamu

Conflicts:
	.gitignore
	modules/UshahidiUI/media/scss/modules/modals/_create-post-modal.scss
Styling Create Set Modal

Still need to work out "Set Photo" form field, but wanted to go ahead and commit and push
Minor fix to dataset
Add method for saving images to configured upload directory
More Styling

This commit works with the "Add a Photo" field and the responsive design.
More Responsive Styling

tweaking the responsiveness
Add implementation for file upload and validation
Override default behaviour with request body so file uploads doesn't have to be a json body
Add validations that are not handled in the model class
Save image details to db
Enabled image module
Save image to database
Save caption to database
Save file location to the database