Raze 1.4.1

This is a bugfix release addressing the following issues:

• handle walls where a sloped floor intersects with the visible part.
• handle wall sprites on orthogonal walls better, covering the case that a wall sprite may overlap two walls with a slight deviation in their position - always pick the closest one.
• fixed handling of badly placed sprites in map validation code.
• fixed inverted logic when checking for dragged sectors in the renderer.
• fixed sky tiling in Polymost.
• Exhumed: avoid accessing undefined memory when loading the sounds.
• Exhumed: fixed surface collisions of projectiles. There was some commented out undefined behavior here, we need to properly define this case.
• Exhumed: removed erroneous target assignment in Anubis AI, leading to infighting.
• Exhumed: Add save game option to in-game menu.
• Exhumed: did some reshuffling on the menu to allow adding a "User map" item and prevent accidental reset of ongoing games, both the items for starting the campaign and the training map are now in a submenu.
• Blood: fixed bad alignment flags for HUD flames.
• WW2GI: fixed gamevars not being allocated for map spawned actors.