add wavefront loader

start adding various scenes to test gpu rigid body pipeline
reserve more memory for shapes (concave triangle mesh can be huge) in GLInstancingRenderer
fix a few crashes when 0 objects

demo/ObjLoader/premake4.lua

@@ -0,0 +1,24 @@
+
+		project "wavefrontObjLoader"
+	
+		language "C++"
+				
+		kind "ConsoleApp"
+		targetdir "../../bin"
+
+	 	includedirs {
+                ".",
+                }
+
+		
+		files {
+			"objTester.cpp",
+			"string_extra.cpp",
+			"string_extra.h",
+			"objLoader.cpp",
+			"objLoader.h",
+			"obj_parser.cpp",
+			"obj_parser.h",
+			"list.cpp",
+			"list.h"
+		}