enable apache2 server as front end for swift

1.install apache and wsgi module
2.config apache2 vhost and wsgi files for proxy,
account, container and object server.
3.refactor apache functions from horizon and swift
into lib/apache

Change-Id: I3a5d1e511c5dca1e6d01a1adca8fda0a43d4f632
Implements: blueprint enable-apache-frontend-for-swift
Add Midonet plugin support to devstack.

Add support for Midokura's Midonet plugin to devstack,
in lib/neutron_plugins and lib/neutron_thirdparty.

Change-Id: I9b4d90eab09bbb21b9ba251a311620e0a21e8219
Launch ceilometer-alarm-* services.

Add ceilometer-alarm-notify and ceilometer-alarm-eval to the set
of ceilometer services launchable by devstack when explicitly
enabled in the localrc.

Change-Id: I1575437c588cf9079f1e3a6c855123eae09c5dac
Add support for vmdk files as glance images

* Adds support for vmdk files as glance images in upload_image function
* Set default image url to use for vsphere driver in stackrc
* Now using a more stable url

Change-Id: If6d45bc8dfd3c812ded5e1bcf69ad7ebd9b64f34
Merge "Launch ceilometer-alarm-* services."
Fix get_pip_command()

Be more flexible in finding pip, especially after we start replacing it

Change-Id: I14b0ac1584aab99c2fe58a78e3a43196ae8130ca
Merge "Add Midonet plugin support to devstack."
Merge "Add support for vmdk files as glance images"
Merge "Fix get_pip_command()"
Merge "enable apache2 server as front end for swift"