libvirt follows a convention where structure types used in its API are
named "remote_nonnull_domain", and optional values for those structures
are called "remote_domain". The generator was translating these into go
names like "NonnullDomain" and "Domain". In go this seems unnatural, and
doesn't match the way the pre-generator version of go-libvirt named
things. So this commit changes the names: "remote_nonnull_domain" will
now be "Domain" in go; "remote_domain" will be "OptDomain". This pattern
is applied to all types.
fcd4f72b3c