This series of patches relates to the cpus parameter and pinning vcpus.
The first patch is a clean-up of getVcpuInfo, which previously only
returned the vcpu to cpu mapping.  This was insufficient for extracting
affinity information.  The patch extends getVcpuInfo to return a dict of
all the fields in xm vcpu-list for a domain.  It also fixes a couple
users of the function and moves them to a new vcpu_to_cpu function which
retains the old behavior of getVcpuInfo.

The second patch adds multiple cpumask support to the cpus variable. We
currently support two formats:

cpus = [ "0", "2-4" ] and cpus = "0|2-4".  The documentation encourages
the use of the python list notation.

The third patch introduces a testcase for the cpus parameter in the
create subset.

The forth patch adds support for the keyword 'all' to the vcpu-pin
operation.  Using 'all' in place of a specific vcpu will apply the
cpumask to all vcpus in the domain.

The fifth patch creates a testcase for the 'all' keyword in the vcpu-pin
subset.