Sprite projection fixes

See merge request !954

G_BuildMapTitle for Lua, G_BuildMapName outside of levels

See merge request !694

on second thought maybe we don't need extra tx clamping, it turns out to be more effort than it's worth (at least for now)

meanwhile, let's move x/yscale calculations down since we don't actually need them until later on

this makes it so that higher fov values can actually let you see all the sprites that should be in the view

added basic culling of papersprites if tx for either is too large, proper clamping to be added later

also removed some commented out old code

it always bothered me that "rot" was used for both of the above, since it confused me as to what it was for every time I look at this function

also add a few comments to explain what tx/tz are

Smooth polyobject movement and other cleanup

See merge request !947

Store waypoints at map load instead of iterating through the thinker list to find them

See merge request !938

I forgot to test OpenGL 

See merge request !953

Encapsulate plane height checks

See merge request !860

# Conflicts:
#	src/hardware/hw_main.c
#	src/p_spec.c

Fix missing sprite column (resolves #135)

See merge request !944

FOF cleanup

See merge request !910

Add missing packet name

See merge request !948

S_StopSoundByID Lua support

See merge request !925

More Demo code cleanup

See merge request !942

Fix A_SignSpin not being usable in Lua or SOC due to an error

See merge request !946

T_PolyObjWaypoint: We can find waypoints in constant time now, so no need to store the waypoint mobj in the thinker anymore

Fix colormap mipmap memory leak on the character select in OpenGL

See merge request !943

Character select in Nights mode.

See merge request !862