Keystone auth in cinder.conf instead of paste-api

cinder.conf supports [keystone_authtoken]. This commit moves the
keystone auth info to cinder.conf so the admin doesn't need to
edit api-paste.ini

Change-Id: Iede28f90a00a65b9c5942191a22a1ec915021c38
Adds section about adding a volume node for block storage.

fix bug 1007528

Change-Id: I1d2d42527583b45a209180209c96d93ec164eba1
Merge "Keystone auth in cinder.conf instead of paste-api"
Merge "Adds section about adding a volume node for block storage."