xenapi: Rename imageupload image

imageupload has been renamed to image

backport: havana
Change-Id: Id69451fed61500a19da62d07221f76889b8af83a
Closes-Bug: #1207550
Added indication of nova.conf

Change-Id: If9875876a8c8a53a55d38598f5cab9ccdc484232
Closes-bug:#1230353
Merge "xenapi: Rename imageupload image"
Merge "Added indication of nova.conf"