Store options in gconf

While it's not the most elegant way to do this I opted to store the
options with "inverted polarity" - i.e., the options that are supposed to
default to "True" are stored inverted since gconf reports an unset option
(first time the user runs the program) as "False".

Signed-off-by: Dirk Hohndel <dirk@hohndel.org>