Make (nearly) everything work on Illumos NGZ.

Importing manifests to Illumos NGZ without using `zlogin` is broken on
OmniOS, but I don't think that's down to SexyMF. All the other tests
pass manipulating services in global->@, global->NGZ and NGZ->@ on
Solaris 10, Solaris 11, and OmniOS. Tests pass in global->global and
NGZ->@ in SmartOS. Haven't been able to test global->NGZ there yet.

Debug logging now records the URI used to connect to the API. This is
useful for digging into failed tests with cURL.