Added a generic interface for stuff that can be disposed of.
Dispose of invalidated mapmesh data.
Avoid retaining references to meshbufs from map overlays.
Added a console command to create tool widgets.
Merge branch 'core'
Merge branch 'master' of git://github.com/dolda2000/salem-client

Conflicts:
	src/haven/GameUI.java
	src/haven/MCache.java
	src/haven/MapMesh.java