FR: Multiple thruster graphical enhancements

[Durandal-Thoth]

This is a request for the following:

• Boolean for AB Trails to respect vector normal of thruster points to prevent trails clipping through ship on reverse thrust
• "glow" texture (the omni-directional sprite at the base of standard thrusters) support for maneuvering thrusters
• Boolean for velocity-based maneuvering thruster "growth"

(bug split into #5912)

[Durandal-Thoth]

I forgot to add, I would also very, very much like an "afterburn state" for maneuvering thrusters where they expand and change textures as standard thrusters do. I'd use a boolean for this as well, so vernier-style burners (more basic maneuvering jets which people may not wish to inherit an aburn effect) are unaffected if the effect is undesired.