Removed BBox, renamed position to origin

I've replaced the BBox class with a pair of inline functions in
check_bounds.hpp. I've also renamed the 'position' variable to 'origin' in
several locations.

These changes are mostly to alleviate ambiguity.

common/utilities/check_bounds.cpp

@@ -0,0 +1,40 @@
+/* Copyright: (c) Kayne Ruse 2014
+ * 
+ * This software is provided 'as-is', without any express or implied
+ * warranty. In no event will the authors be held liable for any damages
+ * arising from the use of this software.
+ * 
+ * Permission is granted to anyone to use this software for any purpose,
+ * including commercial applications, and to alter it and redistribute it
+ * freely, subject to the following restrictions:
+ * 
+ * 1. The origin of this software must not be misrepresented; you must not
+ * claim that you wrote the original software. If you use this software
+ * in a product, an acknowledgment in the product documentation would be
+ * appreciated but is not required.
+ * 
+ * 2. Altered source versions must be plainly marked as such, and must not be
+ * misrepresented as being the original software.
+ * 
+ * 3. This notice may not be removed or altered from any source
+ * distribution.
+*/
+#include "check_bounds.hpp"
+
+bool checkPoint(Vector2 const& origin, Vector2 const& bound, Vector2 const& point) {
+	return !(
+		point.x < origin.x ||
+		point.y < origin.y ||
+		point.x >= origin.x + bound.x ||
+		point.y >= origin.y + bound.y
+	);
+}
+
+bool checkOverlap(Vector2 const& originOne, Vector2 const& boundOne, Vector2 const& originTwo, Vector2 const& boundTwo) {
+	return !(
+		originOne.x >= originTwo.x + boundTwo.x ||
+		originOne.x + boundOne.x >= originTwo.x ||
+		originOne.y >= originTwo.y + boundTwo.y ||
+		originOne.y + boundOne.y >= originTwo.y
+	);
+}