Wall/flatsprite with only front and back sprites

[zrrion the insect]

Wall/flatsprites can have angles just like anything else, having some way to set them to only have a front and back angle (1 and 5 only) would be fantastic.
My current method of doing this is to have two actors with visibility settings set so that you see one from the front, and one from the back and I use A_Warp to stick them together. Implementing a native way to do this would cut actor count down considerable, and make the code much cleaner.

One could make street signs, banners that hang from the ceiling, and other decorative things with a front and back.

As for implimentation, something similar to Player.CrouchSprite (BackSprite, Player.BackCrouchSprite?), where a separate set of sprites would be used for the back. this would have to either be 0 angle sprites, or the 1 frame would be used for the front, and the 5 frame from the backsprite for the back.