reformat register-image command
Check ami_name for length
patch is required (sadly)
Don't rely on external source for diff
Only patch grub-install once

Make this script more re-run-able
Who knows what black magic has been performed on this volume previously!
Normalize reference to ${block_dev}1
fixup 676a4e8a4cbb01da10d18f7733cfe0a5b8f394cd
fixup 64881ed83e5e767adfedc4802deecf3a4721c340
Comments and hvm root device name

Per the block-device-mappings.html doc.
Merge branch 'docs_n_tweaks' into bsdmaster