Enhancement: Volume keyvalue for brush entities

[HugoBDesigner]

What would this enhancement be for?

Entity

Describe your enhancement suggestion in more detail

A lot of brush entities, such as func_door and func_movelinear, have special sound keyvalues that play when they start moving, when they stop, and so on; however, they only play sounds at max volume. It'd be great if, much like func_tracktrain, they all had a volume keyvalue. Extra nice if they also had range controls :)

[TeamSpen210]

You should be able to use soundscripts, though that's a little less convenient.