Edited Budget Graphs

- Differentiated between overspent budget and underspent budget
- Changed colours appropriately
- Edited error of displaying amount spent side-by-side with budget
amount
Added more js to registration

- displays an error message to tell user that their chosen username
and/or password has already been used using "onchange" event
- allowed adding and editing budgets to support spaces for  "categories"
- deleted old "graphs-jplot" folder which is redundant