add option to create mp4 videos from App_AllBullet2Demos, using the

--mp4=video.mp4 note that you have to re-convert for Quicktime
ffmpeg  -f mp4 -vcodec h264 -i test.mp4 -pix_fmt yuv420p test2.mp4
add the option to display text in 3d, used in Coriolis demo

build3/premake4.lua

@@ -94,6 +94,7 @@
 			{
         		'ARCHS = "$(ARCHS_STANDARD_32_BIT) $(ARCHS_STANDARD_64_BIT)"',
         		'VALID_ARCHS = "x86_64 i386"',
+--			'SDKROOT = "macosx10.9"',
 			}
 	end