created table view and navigation controller
added basic interfaces

 * add, cancel, save buttons
 * detail view with title and description
 * segue for add button
added coredata framework
corrected cell label and added corrected segue for editing
edit functionality to save/edit existing todos in localstorage
added PersistentStorage functionality
added loading/deleting/editing of existing todos
added coredata to pre-compiled headers
added managed object model
corrected connection property
Merge pull request #1 from rombald/simple-ui

[WIP] Create a simple user interface