General cleanup on the UserSettingsController stuff. There were 5 different

places that were dumping values for the settings. Centralized all of the
value dumping into a single place. When dumping values that aren't strings
we no longer surround the value with single quotes. When dumping values that
are strings, surround the string value with double quotes. When dumping array
values, assume they are always string values, and don't put quotes around
dictionary values.

llvm-svn: 129826