cd: switch to CD controller code from genplus

same license, much cleaner code
using own dma code though..
cd: switch to CD drive emu code from genplus

same license, much cleaner code
cd: hacks..
fix yet another sync issue..
configure: Deduce the path to sdl-config from the compiler
Menu: Use function plat_get_skin_dir to locate bg image
Add a couple of fixes to allow double buffering to work
Make the platform code provide the key mapping

notaz: fix pandora build
Add support for the OpenDingux platform
Use PBTN_MOK instead of PBTN_MA3 to confirm loading/saving state
Don't include dead code when linking program (saves 48kB)
split base_readme to more traditional files
update gp2x for input changes
remove regs union due to compiler issues

GP2X toolchains are padding the unions no matter what :(
gp2x: hack to avoid 940 reinit

..it used to rely on upper layer to avoid YM2612Init_940() calls
on menu entry
fix use of freed mem
frontend: eliminate osd_text dupes

not only dupe code is bad, it's crasing too
release 1.91