Use browserify to organize javascript files

All generic JS should now be located in `/editorsnotes_app`. A name change is welcome, but I couldn't think of anything better for the moment.

Of course, nothing's ever ideal, so there are a few compromises here. First, most libraries are attached to the `window` object in script tags, as normal. Mostly because they aren't CommonJS compatible, and I don't care at all to pretend like they are. This includes jquery-ui and all jquery plugins (and jquery because of that), citeproc-js and supporting libraries, and wysihtml5.

Second, the index-admin browserify entry point is not ideal yet- I've just made it so that objects which are expected to be attached to `window` are there. This is where we'll make improvements going forward.