Move the locale init to after Sys_PlatformInit().

This makes it actually effective…
Improve purging of unvanquished-common.
unvanquished-common should own /var/games/unvanquished/main.
unvanquished-common: ask whether to download .pk3s and from where
Use navmesh handles; allow class models to refer to earlier ones' navmeshes.
Update messages*.pot.
In the alien spawn menu, always list granger (if enabled).

If advanced granger is locked while the player is not alive then the player
would only be able to spawn as dretch despite adv. granger being listed in
the menu (even if it's opened after adv. granger has been locked). This
workaround ensures that there's always a valid builder option.
Update unlockables info for dead players too.
Improve inactivity timeout handling.

Enable it for dead players. Idling players should be removed from the team
whether alive or dead.

Don't trigger timeout action if the player is in the spawn queue or if the
player is dead but there are no spawns for the team.
Remove debug code which sneaked in with the inactivity timeout changes.
One more cp → cp_tr.
Fix backface culling for directional lights
Fix light debug draw

It flickered in some cases ( e.g. human base )
Add WT_ONE_CLAMP for clamping shadow maps
Use existing rectangle-drawing functions for the confidence bar.
Add backgrounds to the (un)locked item groups.
Merge branches 'gameplay/stable' and 'master' into gameplay/ds
Correctly scale the rendering bounds of md5 models
Remove skeletal bounds cgame hack
Improve rendering bounds for turret

The movement of the barrel of the turret needs to be accounted for in the rendering bounds.