Use nova CLI for network creation

Prefer the "nova" tool over  "nova-manage" for network creation.

Fixes bug 1167657

Patchset adds missing <title> element to Creating Custom Images.
Patchset corrects <productnumber> for <prompt> in Lay of the Land.

Change-Id: Id5d229f530203f361d71ae2c0cd8385297ee3829
Fix a couple missed references to nova/nova-volume

Missed a couple nova/nova-volume references in the new
version of the doc.

Fixes bug: 1168047

Change-Id: I91a9becbce578fb09bf22f7f08e487d1632263b8
Merge "Use nova CLI for network creation"
Merge "Fix a couple missed references to nova/nova-volume"