* We distractedly chose to populate the message from our protective MBR
for GPT/UEFI-only boot media into the 4KB that directly followed the
MBR, which of course is space that is being used by the primary GPT.
* This resulted on systems having to fall back to using the secondary
GPT, which not all appear to be designed to do.
* Alter the code to ensure the protective message is written at LBA 34,
after the primary GPT.
* Closes#1507
* msg.S now reads an ASCII message (with escaped colour sequences)
from the following blocks, which is both more flexible and allows
for more content to be displayed.
* Also adds Bochs testing to the MBR build facility
* Adds USB masquerading according to disk ID in USB part table
* Adds debug feature
* Closes#74 - was due to flags not being properly saved/restored
* Closes#71
* Fixes reentrant INT_13h for some platforms (eg. IBM t43p reenters
INT_13h to issue an SCSI passthrough, AH=0x50)
* Embed MBR as a resource rather than an ms-sys header
