Add timestretching from FS#8894, as written by Stephane Doyon based on work by Nicolas Pitre.  Shouldn't affect playback unless it's explicitly enabled, but let me know if it does.  Currently has a dedicated setting, but maybe inclusion of the code will inspire someone to integrate this with the pitch screen...

git-svn-id: svn://svn.rockbox.org/rockbox/trunk@18446 a1c6a512-1295-4272-9138-f99709370657
9 files changed