fixed recognition of Windows 8.1 sources which contain INSTALL.ESD instead of INSTALL.WIM.NT6 sources boot menus are now handled by BOOTMGR.
This should help loading SATA/AHCI/RAID drivers from virtual floppy on problematic machines
A new option in DPMS and custom F6 floppy menus activates it.
added better handling of illegal characters for Linux/Other ISO source file name.