Add scaffolds for BorrowRequest and Approval
Add comments to explain purpose
Convert attributes to be protected.
Add dependent destroy association to Approvals
Add class method to check if a BorrowRequest would be valid
Add class method to initialize a new BorrowRequest and spawn Approvals for each owner
Add BorrowRequest level status check

Aggregates status over associated Approval records
Limit index requests to own requests
Add inclusion validation to status
Add note about a callback that should be added
Add requested things association to User model
Add BorrowRequest and Approval model views.
Add Font-Awesome for icon font

Bootstrap's default Glyphicons aren't easily colorable.
Move status_icon helper from Approvals to Application level
Add authentication to controllers
Add Approval association
Make status accessible again
Add associations for borrowed thing and borrower
Put request's associated approvals in an unordered list
Add approvals that require action to view