speedups as follows:
~3%/2MHz on high bitrate files (500kbps) on Gigabeat S
~1%/0.5MHz on high bitrate files (500kbps) on Fuze v1
~3%/1MHz (128kbps) - 12%/7MHz (500kbps) on H300
~2%/0.5MHz (128kbps) - 10%/3.5MHz (500kbps) on C200 v1
git-svn-id: svn://svn.rockbox.org/rockbox/trunk@28615 a1c6a512-1295-4272-9138-f99709370657
