North American Signal Texture Mod

This mod replaces the default signal lens texture for all US & Canadian routes. (With the exception of LIRREX as I personally think the default is fine)

-Brand new texture for all signals that use filament lenses for a more realistic look
-Slightly edited the default LED lens so that it stands out a little better at night. Plan on updating this with a new LED texture.

As I become more familiar with the UE editor I would like to adjust the brightness of the signals in the future, with results akin to londonmidland's UK signal mod.

Will update for any new North American route releases.