Organize string-lists alphabetically for completion

This micro patch adds the ability to sort the lists alphabetically
for user interaction. Dirk asked me to do this for location, but
this actually changes for location, divemaster, buddy and suit.

Seems a good thing for all.

Fixes #780

Signed-off-by: Tomaz Canabrava <tomaz.canabrava@intel.com>
Signed-off-by: Dirk Hohndel <dirk@hohndel.org>