fixed in logic bug in a logging statement (missing parentheses)
removed c[12] from logging statement (one c[..] too many).
Fixed an invalid write in disk.cpp:tobin

When the loop is done, i == -1 and so buf[-1] is set 0 (I guess the loop
at one point counted upwards instead). Static memory is initialized
to zero anyway so left out buf[8] = 0;.
Merge pull request #7 from FrodeSolheim/bug-fixes

Bug fixes