Addresses #851, UI fix for Add File button, and copyedit on alert message

Copy edit on field_edit.js.coffee.
Capitalized media object, and changed 'Edit Title' to 'Rename File' for media objects. Addresses #851.
Aligned editor in description box on project page.
Moved Add File button down on projects page (UI).

Apologies for committing app/assets/stylesheets/projects.css.scss. I ended up addressing style elsewhere.  There's no need to commit that file, but it also won't hurt. I mean... it's technically right ;)