Igloo can generate on ice

Sound/visuals difference when shooting through "air" between stairs/bottom slap and water on top

Player spawnpoint used in monster spawning seems to be unaffected by sleeping in bed or /spawnpoint command

The big tree generator handles tree height variable incorrectly

Stairs-block collision ray tracing method forgets to tell when it has finished.

Random destination routine has a small statistical tendency to move more north west (fix included)

Village siege's spawn location is calculated incorrectly (fix included)

Real zombie sieges fail to start (fix included)

Structures can be generated with different parts at different height

Cave/tunnel generation may cut tunnels a bit too soon (fix included)

Nether cave/tunnel generator produces incorrect/cut tunnels

The generation of "terrain" surface layer in Nether produces local straight artifacts/glitches (partial fix included)

The generation of terrain surface layer produces local straight glitches (fix included)