dom0 rootwrap - case insensitive xenapi section

As per change https://review.openstack.org/33429 the config sections
became lowercase. This patch makes the quantum-rootwrap-xen-dom0
rootwrap to be case insensitive for the xenapi section.

This patch also changes the default config file to use a lowercase
xenapi section.

Fixes bug 1195781

Change-Id: Ic24feb1a9ad6f8823745b1febd4a0edd54e73498
Support a timeout argument when instantiating a bigswitch plugin

The timeout argument overwrites the timeout value set in the config file.
The change permits any standalone script to interact with the bigswitch controller
through the quantum plugin with customized timeout value without changing the plugin
behavior.

Fixes: bug #1195923
Change-Id: I17954e70d661e7e7d5156c34c08b7c96bb3203ce
Merge "Support a timeout argument when instantiating a bigswitch plugin"
Merge "dom0 rootwrap - case insensitive xenapi section"