On Unix platforms unicode is implemented through UTF-8 which is
transparent for applications. But on Windows a UTF-16 dialect is
used which needs alteration at application side. This wrapper is
another step to unicode support on Windows, now we can replace
fopen() by a function that converts our internal UTF-8 pathes to
Windows UTF-16 dialect.
This is a noop for Unix platforms. The Windows build is broken,
the compiler errors out in shared.h. This will be fixed in a
later commit.
Caveats:
* fopen() calls in 3rd party code (std_* and unzip) are not replaced.
This may become a problem. We need to check that.
* In the Unix specific code fopen() isn't replaced since it's not
necessayry.
Revert "change several strcat calls to Q_strlcat calls"
This reverts commit ab879f1bc7.
Revert "change (v)sprintf calls to (v)snprintf calls"
This reverts commit b46e210d76.
