draft update to notes.md for boot-elements
Fill in nova-compute log path in notes.md
a few more updates

- use load-image
- copy stackrc out of VM
- load your ssh key into nova
Use correct path to `scripts/load-image` in notes.md.
Update `nova boot` command in notes.md.
Update notes.md to allow VirtualPowerManager ssh access to host.
Make load-image load correct kernel/ramdisk.
Emphasise that all commands in notes.md are to be run on host.
Merge branch 'notes-use-boot-elements'

Conflicts:
	notes.md