updated fds audio code to be more in line with whats currently known …

…about it

Update README.md

added in mappers 40, 43 and 50

-added support for mapper 224

-improved vrc7 audio emulation, now volumes behave more accurately
-added newly dumped data for accurate vrc7 instruments

-added support for mappers 80, 82 and 207

-clearing prg ram on first creation so theres no random garbage in new saves

-added support for mappers 64, 77 and 158

-some corrections to mapper 30
-disable overscan by default

-slightly reduced default volume to reduce potential clipping

-implemented mapper 30, should work in both flashable and non-flashable configurations

added support for mappers 28,31,107,132,136,137,138,139,141,172,173,1…

…93,221,229,230,235 and 237 and improved implementations of mappers 36,45,58,62,112 and 225

-various small changes to further increase overall performance

-corrected small inaccuracy in one of the unofficial cpu instructions
-changed the logic of the apu sweep to produce a better output

update this too...