* GRUB have cherry-picked patches from the "BootHole" vulnerability fix at
https://lists.gnu.org/archive/html/grub-devel/2020-07/msg00034.html and
have applied them to their 2.04 GRUB loader.
* This results in breakage with "error: symbol 'grub_calloc' not found" when
using the release GRUB 2.04 version of core.img.
* Therefore, we too cherry-picked some patches to apply on top of GRUB 2.04
release to make our core.img compatible with Ubuntu 20.10.
* Closes#1616
* Also increase the maximum write stride for ms-sys to 64 KB (required to
write the GRUB 2.05 bootloader which is larger than 32 KB) and update hash DB.
* And reverted grub2 to the one from b3947fc026 (reverts commit 8b47e95eb5)
since FreeNAS doesn't work with the older one.
Sorry "Super Grub2 Disk" and other older GRUB2 based tools, but you'll need to
update the Grub version you use if you want to be compatible with Rufus.
* Closes#244
