Created Incomes controller and views
Added income methods, generalized error partial

- Incomes
- new (method+view)
- show (method)
- error partial: render passes it an :object variable that corresponds
to whatever object the view is dealing with; this way the error partial
can be used with more than one model
Fixed typo in incomes new view
Fixed github mixup

Manually copied over the 6 files that Ben commited to the deleted
signin_signout branch; copied them to my local copy of the
income_reporting branch, then pushed the income_reporting branch and
deleted the signin_signout branch
Prettied up income and user creation views
Created view that lists users

Created view and controller methods for displaying lists of users
(users#index); made user encryption methods in model private; added
full_name function to User model