1.2b:
vcr6 sound channel for mapper24 and mapper26 is added.
a sound reset button is added to menu>settings>config, which is used when the sound goes bad,
when close and open the DS, this is probly needed.
Mapper253 is added.
fds saving is disabled when the game is not a fds.

CRITICAL NOTE:
the sound rendering has almost reached the ability of arm7, so .....
the arm7 will auto detect the IF, by which to fix the mess of sound.