Fix/suppress plethora of integer conversion warnings on x64 Visual Studio build.

src/ifcparse/IfcUtil.h

@@ -187,11 +187,11 @@ public:
 	}
 	outer_it begin() const { return ls.begin(); }
 	outer_it end() const { return ls.end(); }
-	int size() const { return ls.size(); }
+	int size() const { return (int)ls.size(); }
 	int totalSize() const { 
 		int accum = 0; 
 		for (outer_it it = begin(); it != end(); ++it) { 
-			accum += it->size(); 
+			accum += (int)it->size(); 
 		} 
 		return accum; 
 	}