ZFSBootMenu 0.6.5

This is largely a bug-fix release, built on top of Linux 5.3.10 and ZFS 0.8.2 for x86_64 and ppc64le (POWER8+).

• Properly sort the list of kernels by version, so that 5.x.10 is
  considered a higher version than 5.x.9
• Correctly set a return value for all zfs load-key operations
• Greatly simplify when a BE is mounted when trying to find kernels in
  /boot
• Only add a BE to the environment list if one or more kernel/initramfs
  pairs were found