* New beta recovery.bin which can update the VLI EEPROM before
start.elf is loaded. This is the recommended and default method
because no USB devices will be in use at this stage.
* Extend the USE_FLASHROM configuration to use the vl805 tool
to program the VL805 directly.
* Generate SHA256 checksums in .sig files for the bootloader and
and VL805 images. This is required by the new recovery.bin to
guard against corrupted files being flashed to the EEPROM(s).
* Various variable renames to distinguish between the bootloader
and the VL805 images.
If the size of bootconf.txt is reduced then set the unused data
to all ones instead of leaving garbage at the end. The EEPROM
header contains the actual file but this makes it easier to
verify the image and makes overreads more obvious.
