Major improvements to GUI

Pretty much finished all of the GUI
- When you hover over a subject code, it'll preview all the available
class times
- When you hover over a class time it'll preview just that class time
- If you click a class it will add it to the calendar
- If you're unhappy with the class you "selected" you can remove it
- Provides an output of the class lists so you can be ready for class
registration

Still having problems with the whole 'import times, open page, show
times' thing (if the tab isn't already open it will "lose" the data for
the first subject you try to import so you have to go back and click it
again)