K 10
svn:author
V 6
tsoome
K 8
svn:date
V 27
2018-08-22T10:04:42.709648Z
K 7
svn:log
V 239
loader: bios loader should allow to chain load a file

The current chain command does accept only device, allow also a file to be used,
such as /boot/pmbr or /boot/mbr (or stored third party MBR/VBR block).

Also fix file descriptor leak.

END