Backbone: begin to add tags to task form.
Bugfix: could not submit multiple tasks in a row (caused edit of previously...

... submitted task.) Also, some partially implemented features for creating
tags with tasks.
Backbone / styling: add tag display to task index. Style them.
Backbone: Tags can be added when tasks are created / editing.

Note: major bug in the implementation here. Must revisit!
Additionally, fixed several bugs in dealing with orphan views.
Added library for multi-select.
Remove extraneous file.
Rails task model: comment out buggy code.
Minor commit.