Split generation models in biome and transition. Create TransitionCorner object
Merge branch 'master' of https://github.com/stevenremot/npath-adventurer
Merge branch 'master' of https://github.com/stevenremot/npath-adventurer

Conflicts:
	src/generation/models/transition.lua
Merge branch 'master' of https://github.com/stevenremot/npath-adventurer
Add higher walls