GitHubFriends- Rename listItems to users

No functional changes. For readability
TTT- Tic Tac Toe Initial Commit
STA- Simple Tasks App Initial Commit

We’re going to have 3 VCs:
1) Groups VC (that’ll have groups of lists)
2) Items (each group will contain a list of items)
3) Edit Item (allow you to edit a particular edit item)
STA- Implementation based on design layout
STA- No functional changes
STA- We now save group data

- Removing hardcoded test data for groups and items
- Group info is now saved to disk (this still needs to be done for
items!)
- User must click save / cancel buttons when adding / editing a new
group / item.
STA- Add drag button to change item priority

See screenshots item_high_priority.png & medium to see layout. As we
drag (finger must be on button) then we’ll move the item name along
with the ‘underline’ and the button along with the drag. Tapping
elsewhere on screen will make keyboard disappear.