Added support for ISO virtual disk on Server 2003 and Server 2008 via 3rd party utility.

While Windows 2003 and 2008 don't support native mount of an ISO file, this can be accomplished via 3rd party utility.

Built to use Virtual CloneDrive from Elaborate Bytes/SlySoft, code checks for device presence and location of mount executable. If all are present, the ISO is mounted using the first available virtual device. Pre-existing cdrom based code is leverage from that point onward.

Virtual CloneDrive is freeware, and available from  www.slysoft.com. Software must be pre-installed by user in their image.