Rename 'syschk' symbol in the linker config file, which forces inclusion
of the 'system check' load chunki, to '__SYSTEM_CHECK__'.
atari-asm.cfg linker config file
Put EXE header and main chunk load header into a single file --
it makes no sense to be able to include/exclude them separately.
Merge pull request #56 from groessler/something_to_pull

atari-asm.cfg