Log message

Add an example that exports the contents of Graphics framebuffer to a Targa file

	Modify	/trunk/gfx/draw_triangle/ocaml/main.ml	diff
	Add	/trunk/gfx/save_bitmap	diff
	Add	/trunk/gfx/save_bitmap/ocaml	diff
	Modify	/trunk/gfx/save_bitmap/ocaml/OMakefile	diff
	Modify	/trunk/gfx/save_bitmap/ocaml/main.ml	diff
	Delete	/trunk/gfx/save_bitmap/ocaml/screenshot_triangle.png	diff
	Add	/trunk/gfx/save_bitmap/ocaml/tga.ml	diff