Reduce  unnecessary 2.7 versus 3.4+ differences in idlelib/configDialog.py.
Only change 2.7 version.
Remove ".keys()" from "x in y.keys()" (leave .keys() elsewhere alone).
Change "string.join" to "' '.join" (and string.join(s, ';') to ';'.join(s)).
Change spacing to match 3.4 (will later make spacing changes to both).