Style account dropdown menu
Modify height of viewports on window resize
Change note detail viewport width on window resize

Also fixed a bug with the vertical resize work on the note detail
viewport.
Add dropdown menu to switch a note's notebook
Track the current tag & change it on tag selection
Style current tag button
Filter notes list based on the selected tag
Handle exception when there are no notes.
Add handler to remove the current tag & unfilter
Begin note info dropdown
Hide the info menu for the moment.

Will come back to it in a bit. I've basically realized that the api
needs refactoring if tags are going to work in a sane way.
Remove old, unused rails views and resources
Remove old, unused rails controllers