cleanup
show sky
SeTileDataNoHeight
fix slope creation
add show water
add cursor move with keys
Add GetPath/GetPathReverse to AStar
astar: add GetPathNodesReverse
add 2D ToSurroundingPoints
add rivergen
comments to mwcrandom
fix terraingen
clean up river gen
add Min methods
clean
remove unneeded seed
no trees in the river
make terraintest identical to game
rename heightmap to levelmap
rivergen: fix the random