move extracting planes to camera header

* since it related to view frustum / camera it should be in thie header or separate header called frustum.h
* update LICENSE to add authors of algorithm

LICENSE

@@ -52,3 +52,9 @@ LICENSE:
 
   Computing Euler angles from a rotation matrix (euler.pdf)
   Gregory G. Slabaugh
+
+4. Extracting Planes
+Fast Extraction of Viewing Frustum Planes from the World-View-Projection Matrix
+Authors:
+  Gil Gribb ([email protected])
+  Klaus Hartmann ([email protected])