premultiply the accumulated transform for labels and thrusters, simpler
keep the orientation when adding tag points
press T to display tag points
use camera positions from the model when available
collect gun properties into a single struct

one day we'll have a proper gun class
get gun position and direction from model
initialise old-style gunmounts, we still need separation and orientation
emit deprecation warnings for camera & gunmount shipdef fields
Merge branch 'gunmount-cockpit-tags'