Changes:

• Improved help message
• Optional workaround to make buggy BIOS happy when they think that devices without partition boot flag toggled isn't bootable

Fixes:

• Non-ASCII filename in source image becoming garbled in non-ASCII locales
• Issues on the ENTER keystroke prompt in Legacy PC booting

Signed-off-by: Federico Damián Schonborn <federicodamiansch@gmail.com>

Successfully wrote a Windows ISO image and booted.