Moth update.

Fixed missing LDR cubemaps.

-Night version!
-Added light props to daylight version for consistency with night version.
-Changed ladders to func_ladder (CSS/Old Half-Life ladders). I'm not sure why you would want this, but there it is.
-Adjusted alpha clip threshold on the tree material, slightly adjusted UVs on one of the cards to fix a hard edge that looked bad.
-Adjusted alpha clip threshold on the cloud material.

Updated some materials, added navmesh and ai nodes, redid the shader and lighting system for the trees to prepare for night version.

Please do let me know in the meantime if you encounter any problems with the changes.

Initial addon creation.