Deleted previewdatacopy.asm which was for SRAM Trace which we no longer
support. Password moved to $703000. 32-bits at $FFE0 in ROM (unused
hardware vector) now burned into $702015 in SRAM with ROM name.
Changes to save.asm and fileselect.asm to account for new WRAM buffer at
$7F6000 saved at $700500, length $1000.
Moves and additions noted at bottom of sram.asm, to be removed later.
