Polishing up the add device form

- adds an error-view
- add formfactor model and view
- form now saves serial and formfactor
- updates the device-model with validation method
- updates the device-collection to use new model validation
- add unit test for device-model validation
- updated underscore to include underscore.string
- minor modification to device-grid and main scss
Merge pull request #16 from BoiseFED/polishing_js_form

Polishing up the add device form