gconftool-2 module

A module I wrote for making settings changes using `gconftool-2` when using anisble to provision my pc. Figured I'd make a PR for this and see if there's interest in merging this/reccomended changes.

It's not 100% feature complete. i.e. there is no `unset`.
Here's the reference page. http://linux.die.net/man/1/gconftool-2