Use print function rather than print statement

This is for Python 3 compatibility, since Python 3 does not support
the print statement, only the print function.  (Python 2.6 and 2.7
support both, depending on whether a __future__ import is used.)

Paths containing "xen" were left alone, because of comments in a
couple of the files indicating that the XenServer code needed to be
compatible with Python 2.4.

Fixes bug 1226943

Change-Id: I23b804a4d99500b4acf81dd19645ab06dfcc9f1c
Merge "Use print function rather than print statement"
xenapi: post install scriptlet to rpm

A freshly installed XenServer requires some modifications in order to be
able to run OpenStack. Nova contains an rpm specification to create a
package with the dom0 plugins, however installing the rpm is not enough.
Some more actions need to be taken:
 - create /images, link to a directory within the local SR
 - setup an ssh keypair, and authenticate it with the host
This change adds a post script to the nova plugins rpm spec file, so
by installing the rpm on a XenServer, it is ready to run OpenStack, no
further manual actions needed.

Change-Id: Id57e3a3ab2782550468c6aa4c01059ceb7cc81ab