#1 POSIX compliance

[Anonymous]

CHANGES:
- strcmpi() is not part of POSIX, use strcasecmp() instead.
- strupr() is not part of POSIX, but can be done in a simple for()-loop.
- access() is not required, if the file is not accessible, fopen() will fail.
- <io.h> is not available on all platforms, and POSIX defines access() in <unistd.h> (but we don't need it anyways).

[Nobody/Anonymous]