Improve state selector on admin filterer

This disables the chzn de-select on edition state filterer, making it
behave more like a traditional select field. It also removes the
search/autocomplete when there are less than 10 options.
Tidy up admin/editions#index layout

Primarily adjusting the main column layout and table column widths to
give everything a bit more breathing space. All columns except the
main title column have a fixed width, allowing the title to expand to
fill the remaining space.
Update chosen.jquery.js library

The latest release is fully responsive, so no more weird overflowing
select fields when resizing your screen.