Make memory_parameters= more robust.
Make memory_parameters= more robust.

Re-write libvirt_dom_set_memory_parameters to be more like
libvirt_dom_scheduler_parameters_set.  The new version is
more generic, and will work for any future memory parameters
that may come along.  It will also find failures or invalid
parameters more easily than the old version.

Signed-off-by: Chris Lalancette <60b62644009db6b194cc0445b64e9b27bb26433a@redhat.com>

pronix/ruby-libvirt,pronix/ruby-libvirt,pronix/ruby-libvirt