qemu: Introduce qemuBuildNetCommandLine
qemu: Introduce qemuBuildNetCommandLine

Add new function to manage adding the network device options to the
command line removing that task from the mainline qemuBuildCommandLine.

Signed-off-by: John Ferlan <87558058f6f829e5ec976c8ef960720af4ff9c7d@redhat.com>

eskultety/libvirt,olafhering/libvirt,datto/libvirt,zippy2/libvirt,jfehlig/libvirt,libvirt/libvirt,datto/libvirt,eskultety/libvirt,jardasgit/libvirt,nertpinx/libvirt,crobinso/libvirt,VenkatDatta/libvirt,olafhering/libvirt,eskultety/libvirt,libvirt/libvirt,jfehlig/libvirt,jfehlig/libvirt,zippy2/libvirt,taget/libvirt,crobinso/libvirt,fabianfreyer/libvirt,datto/libvirt,fabianfreyer/libvirt,jardasgit/libvirt,taget/libvirt,nertpinx/libvirt,fabianfreyer/libvirt,datto/libvirt,andreabolognani/libvirt,VenkatDatta/libvirt,andreabolognani/libvirt,taget/libvirt,libvirt/libvirt,andreabolognani/libvirt,olafhering/libvirt,taget/libvirt,jardasgit/libvirt,olafhering/libvirt,nertpinx/libvirt,VenkatDatta/libvirt,crobinso/libvirt,zippy2/libvirt,VenkatDatta/libvirt,jardasgit/libvirt,eskultety/libvirt,libvirt/libvirt,VenkatDatta/libvirt,andreabolognani/libvirt,jardasgit/libvirt,taget/libvirt,zippy2/libvirt,nertpinx/libvirt,fabianfreyer/libvirt,andreabolognani/libvirt,jfehlig/libvirt,nertpinx/libvirt,datto/libvirt,eskultety/libvirt,crobinso/libvirt,fabianfreyer/libvirt