There was an incompatible change to the json module api between py26 and
py27, causing gbz80disasm to not work with py26. The fix is to simply
alias the new loads method to the old read function.
A possibly better plan might be to not support py26 at all.
This removes DisAsm from romstr.py, which was the only reason that
gbz80disasm wasn't able to import RomStr from romstr.py.
DisAsm was an experimental gbz80 disassembler that was meant to replace
gbz80disasm eventually. The goals were to write cleaner code and write
more unit tests. But it never worked and the code quality looks close to
being the same as gbz80disasm anyway.