use new package name to replace python-pyparsing

on rhels6.4/centos/fedora, there is pyparsing instead of python-pyparsing.
So modify the neutron_python_packages default list. And add one special
case for suse. I also move the messagebus for redhat/centos in the case
statement.

Change-Id: If48d5a35c227223114ac23d5add83d2684a8b717
Closes-Bug: #1244559