Updated DatabaseConnection to fix local branch
Updated gitignore

Updated the gitignore to hide the database files from repo.
Added ViewBill GUI

Added ViewBill GUI, some TODO left in code.
Added ViewBill GUI support.

Added event handlers for ViewBill button.
Added getBills method, with accountID parameter.

Required for ViewBill GUI.
Merge pull request #1 from SEFall2013UTD/zack

Zack