Config Reference update options and regenerate

Move some generic hypervisor variables to libvirt.
Regenerate against current nova master, mark new options and add new
tables.
Reference new tables in Config Reference.

Change-Id: I87a4e5e7e8284e36b365f60f26ab0bee7126fdd6
Closes-Bug: #1267316
Closes-Bug: #1367224
Closes-Bug: #1367012
Merge "Config Reference update options and regenerate"