Add Item : save indicator is functional

Controller, ViewController, and ViewModel are now developped and
functionnal regarding the save status.
Everything is plugged together so the save button is enabled only
if the viewmodel text is not empty or nil.
generating code coverage
added coveralls support
trying to fix build
Fixing coveralls.rb mode
Removed coverage for test files
Added coverage badge in README.md
Fixed Badges for screenshots
Removed unused code
Merge branch 'add-item-to-inbox' of github.com:raphaelmor/MZTD into add-item-to-inbox
Added bindings between ViewModel and view
Plugged view into app
Code Formating
Automatically dismiss keyboard when return is pressed
Added Basic Core Data Objects and PersistentStack
Store can create a new item
Added order in newly created item
Added save to store
ViewController Forwards save to controller
Controller saves when save is called