* all: Patch from Måns Rullgård <mru AT mru DOT ath DOT cx>

"Here's a patch that adds some kind of rate control.  I suppose it is
 by no means perfect, but it's much better than constant quantizer.  It
 also has a very crude scene change detection that sometimes avoids a
 buffer underflow by reencoding oversized P/B frames as I frames."



git-svn-id: svn://svn.videolan.org/x264/trunk@17 df754926-b1dd-0310-bc7b-ec298dee348c