win32 __PHYSFS_platformRealPath

[Ryan C. Gordon]

> What is this function for?
>
> Seems to only be used on the userdir and basedir. Don't these functions
> return the real path anyway?

It's meant to resolve all symbolic links and relative path elements.
Obviously symlinks are a non-issue on win32, but there could still be
something like this:

putenv("HOME=..\\.\\..\\myhomedir");  /* hypothetically speaking. */
PHYSFS_init();

We'd want to resolve that to the fully qualified path (such as
C:\data\myhomedir, or whatever that would resolve to).

Right now it's only used for home and user dirs, since this is only a
concern with paths in platform-dependent notation. Once the initial
directories are set up (write dir, search path, etc), then PhysFS checks
for (and disallows) "." and ".." directories.

--ryan.