Grauschweif's Map Elements

Adds several elements and features for map makers. # Game-Play: can load maps made with MapResizer (without Luke's mod) free camera movement by default # New Elements: ## Water Sources a water source that ignores seasons a water source / drain that only halves strength during drought a soil contamination source without flowing water a soil irrigation source without flowing water ## Irrigation Sources * a well that is also a portal Wells go dry with drought, may spill with monsoon. They are 'indistructable'. A well offers a portal to any other well on the map. Distance relates to height (but is faster than walking otherwise). # Known Issues Experimental release. Irrigation can in certain cases 'jump' columns when removing / adding terrain right below them.