Added very basic notepad switching.

Temporary UI, and notepads must currently be created manually.
Basic notebook addition now works
Migrated to a <form> for creation. Also added a default notepad.

Minor: fixed inconsistency: "notebook" --> "notepad"
Fixed a bug with empty notepad names
Added notepad deletion
Working on notepad-swap styling
Tied together the UI with a Bootstrap modal
More informative default pad, though still lacking.
Removed a redundant stylesheet link