Update 0.9.012 Happy New Year!

+ Fixed сrash with Imps pathfinding
+ Fixed crash related to Dragons
+ Fixed crash and serious memory leaks relating to some creatures
+ Fixed bug: dwarves sometimes spend two blocks of earth when build one
+ Fixed: dwarf movement shaking in direct control
+ Fixed bug with dwarf moving over holes
+ Fixed: background behind the trees
+ Fixed bug with entering into Snow World
+ Fixed bug: dwarves did not climb out of lava
+ Fixed several minor bugs