[openstack|compute] Allow booting a VM with NICs (net_id, port_id, fixed_ip)
[openstack|compute] Use attribute accessor for nics
fix bug where servers.all was ignoring filters due to hash merging in the wrong direction.
[libvirt|compute] handle missing <system> tag in libvirt node info

Fixes #1652: libvirt provider requires a field that libvirt specifies as
optional
Merge pull request #1676 from domcleal/1652-missing-systeminfo

[libvirt|compute] handle missing <system> tag in libvirt node info
Merge pull request #1673 from aussielunix/Bug-servers-all-filter

[vsphere] fix bug where servers.all was ignoring filters due to hash merging in the wrong direction
Merge pull request #1669 from frodenas/boot_with_nics

[openstack|compute] Allow booting a VM with NICs (net_id, port_id, fixed_ip)