Implement a WinLoadFileIcon wrapper to "lazy load" icons from slow file systems

[Gregg Young]

What we could do is Implement a WinLoadFileIcon wrapper. This would look at the file system type and either load the icon immediately or post a message to the object window. The wrapper would return a generic icon for the delayed loads. Eventually, the object window would load the true icon and update the container, assuming the CNRITEM still exists.

For performance, we would probably want to maintain an array of DRVINFO structures, indexed by drive number, that caches the file system type along with other useful drive status. The driveflags could move to this structure too. Since mapped drives can come and go, some care will be needed to keep the DRVINFO data up to date