Summary: Add documentation for the KVM support for OpenVswitch

Modified the KVM installation instructions with an example on how to use
the openvswitch bridges.

Modified the Nicira NVP plugin documentation with support for KVM

Updated the Nicira NVP docs to mention that it can be configured using
the UI now.
Merge branch 'master' into cloud-agent-with-openvswitch

Conflicts:
	plugins/hypervisors/kvm/src/com/cloud/hypervisor/kvm/resource/LibvirtComputingResource.java
Summary: Apply feedback from Wido

Better checking on VlanID

Correct speling mistake