conf: domain: Introduce virDomainDeviceIterateFlags
conf: domain: Introduce virDomainDeviceIterateFlags

Validation of domain devices is accomplished via a generic device
iterator which takes a callback, iterates over all kinds of supported
device types and invokes the callback on every single device. However,
there might be cases when we need to alter the behaviour of the
iteration (most notably skip or include a group of devices). Therefore,
this patch introduces iterator flags.

Signed-off-by: Erik Skultety <2c14d38fa47c8799f1b9c16280abe27f8edfec6e@redhat.com>
Reviewed-by: John Ferlan <87558058f6f829e5ec976c8ef960720af4ff9c7d@redhat.com>

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