Created the loadGameMap() function, still incomplete

Although the overall logic of this function is finished, I still need to
write the callbacks for RegionPager's onNew and onDelete.

I've also tested this using a hand written save/index file. I've written
up a map file format by hand, and I'll be implementing it over the next
few commits.

common/region_pager.hpp

@@ -47,6 +47,9 @@ public:
 	void SetOnNew(regionCallback_t f) { onNew = f; }
 	void SetOnDelete(regionCallback_t f) { onDelete = f; }
 
+	//TODO
+	//void Prune(int camX, int camY, int screenW, int screenH);
+
 	//accessors and mutators
 	int SetWidth(int i) { return regionWidth = i; }
 	int SetHeight(int i) { return regionHeight = i; }