fixed settings.json.dev; added fauxton & cachebuster
fixed .css concat ordering in index.css

This change removes the loading of .css files
from /addons/**/assets/css/*.css. Putting those
back is an option, but since unused at present
I saw it as a separate case for adding back
if/when desired.
nv.d3.css is the one CSS used in Fauxton

And now it is loaded before the fauxton.less
file. Other options would include moving/renaming
it (to a .less file) and making it an @import.
Not necessary this time, but may be for other
needed CSS.