Updated for all checksum ranges and header locations allowed by the US SMS BIOS, and source tidied up a bit more.
Updated for checksum range 1 (Chuck Rock 2), also cleaned the source a bit
Updated for SDSC tag 1.01
Added the ability to read the header in Codemasters roms, figured out how their checksum works, and added the ability to check that.
Updated with newfound GG product number information
Moved release notes to a listbox, so Eric can write even more of them :o)
Updated with newfound Codemasters checksumming information
Various things... I forget exactly what