Add ability to specify arbitrary key value pairs to be used by driver when launching instance for OpenStack Compute (nova)

The use case I would like to support is the passing of a kernel command line at instance launch time. The driver for docker could use this metadata to pass environment variables it needs. Some discussion around this took place on the mailing list: http://lists.openstack.org/pipermail/openstack-dev/2013-December/02...

Expose ability to configure kernel and ramdisk via REST and CLI. And add ability to pass in kernel command line at instance launch time for OpenStack Compute (nova)

In an effort to streamline the image creation process using OpenStack the following observations have been made: nova-compute RPC API provides that ability to specify ramdisk_id and kernel_id when creating an instance [1]. However, the REST API does not expose this functionality and the kernel_id and ramdisk_id are...