Changelog:

- Fixed unknown price values for addons given by missions
- Spy missions should not choose wormhole sectors anymore
- Promoted toggleautoaim from macro to internal command. a
one-time error in the console will appear. This is normal.
- Added AutoAim indicator to HUD
- Added AutoAim indicator/notification interface options.
- Changed 'Select Weapons' to 'Select Weapon Group' in HUD
Help menu
- Fixed 'Select Weapon Group' value in HUD Help menu to
properly show '1-7'
- Changed 'Fire * Weapon' to 'Fire * Weapons' in menus
- Removed missionhelp command because it is obsolete
- Windows Sound driver should work in rare cases where it
doesn't find any audio devices
- assert and error are exported to public lua interface
- Added custom 'thread' api to the public lua interface
- gksound.GKLoadSound{soundname="soundname",
filename="filename"} function. "soundname" is what is sent
to gksound.GKPlaySound("soundname")