Add the GPU rigid body pipeline from https://github.com/erwincoumans/experiments as a Bullet 3.x preview for Bullet 2.80

Extras/RigidBodyGpuPipeline/build/findOpenGLGlewGlut.lua

@@ -0,0 +1,52 @@
+	-- todo: add Apple OpenCL environment vars
+
+	function initOpenGL()
+		configuration {}
+		configuration {"Windows"}
+			links {"opengl32"}
+		configuration {"MacOSX"}
+ 			links { "Carbon.framework","OpenGL.framework","AGL.framework"} 
+		configuration {"not Windows", "not MacOSX"}
+			links {"GL","GLU"}
+		configuration{}
+	end
+
+	function initGlut()
+		configuration {}
+		configuration {"Windows"}
+
+			includedirs {
+				projectRootDir .. "../../Glut"
+			}
+			libdirs { projectRootDir .. "../../Glut"}
+		configuration {"Windows", "x32"}
+			links {"glut32"}
+		configuration {"Windows", "x64"}
+			links {"glut64"}
+	
+		configuration {"MacOSX"}
+ 			links { "Glut.framework" } 
+	
+		configuration {"not Windows", "not MacOSX"}
+			links {"glut"}
+		configuration{}
+	end
+
+	function initGlew()
+		configuration {}
+		configuration {"Windows"}
+			defines { "GLEW_STATIC"}
+			includedirs {
+					projectRootDir .. "../../Glut"
+			}
+			libdirs {	projectRootDir .. "../../Glut"}
+		configuration {"Windows", "x32"}
+			links {"glew32s"}
+		configuration {"Windows", "x64"}
+			links {"glew64s"}
+
+		configuration{}
+	end
+
+
+