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
Fix validaiton of --clean

Check !== FALSE since passing --clean just sets it to NULL
Make sure we handle duplicate users properly
Import: Delete users with NULL username when passing --clean
Add @todo to handle existing categories during import
General UI Fixes

Tweaked small things here and there

added .sass-cache to .gitignore
Merge branch 'map-tweaks' into create-post
Convert indentation on CreatePost.html to tabs
Remove padding from text/email input fields

Remove padding because it breaks in firefox and hides the contents of
the field.
Ping @middle8media can you have a look at this and figure out what this
should be to work as expected in FF and Chrome? Had this same issue
with similar styling on wvspeed..
Rough beginnings of create post wiring

Starting to wire up the beginnings of the create post process.
This commit adds an event handler when the create post form is
submitted.
I'm using backbone.syphon to pull data out of the form and serialize it
in a
form we can use for models. I'm not doing any handling of exceptions yet
so all saves will fail.
Stop loading backbone.validateAll until we're actually using it
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
Add padding back to input fields, adding height to fix FF/Chrome mismatch
Prevent navigation when clicking on 'create post'
Start using backbone-forms to generate the form HTML

Pulling out all the hard coded form html and replacing it with backbone
forms generated html. Far from perfect, but getting us started and
allowing for extension with custom fields.