xenapi: display IP and DevStack result on console

The devstack setup service can update /etc/issue, displaying the status
of the installation and the VM's management IP. With this change, after
the devstack service finsihed, the login prompt will look like this:

OpenStack VM - Installed by DevStack
  Management IP:   10.219.3.108
  Devstack run:    SUCCEEDED

DevStackOSDomU login:

This helps people to log in to their system.

Change-Id: Idd6bbd5faf9ced5618cd3e95191bfc3b89473fa2
Setup user and endpoints for Savanna

* create savanna user with admin role for auth token checks
* create service data_processing
* create savanna endpoint
* use savanna user for auth token checks

It's needed for running tempest tests.

Change-Id: Iff26960746e36012c275f43c0de0dedcaebc8b0a
Merge "xenapi: display IP and DevStack result on console"
Merge "Setup user and endpoints for Savanna"
XenAPI:  Increase DomU's memory

Devstack has been increasing in complexity, and if we use too
much of our memory it can lead to fragmentation which in turn
causes a DomU error and a failure of random tests.

Change-Id: Ide9cc84625caed4e35a64a47ee1e92a6cd567651
XenAPI: Update DomU to Ubuntu Saucy

Driven by a race condition in LVM being hit in the tempest
tests.  This is a locking race between a file lock and a
semaphore which is fixed in 2.02.96-5.

Change-Id: I8a8c215c90a0602288292ffd06b7694d2db6219e