util: change gitversion to report committer not author date
vo: fix registry list update bug

Make sure that the searchable registry list update action does not add
the same registry multiple times to the list.
vo: modify registry protocol selection UI

Now the registry protocol selection (RegTAP or RI1.0) is done using
a combobox adjacent to the registry URL selection, rather than hidden
away in a menu.  This may still not be the final UI for registry
selection, but it makes it more obvious what's going on.
vo: change URL for NVO/VAO RI1.0 registry

On advice from Theresa Dower (STScI) I have changed the RI1.0 endpoint
for the STScI registry from
"http://nvo.stsci.edu/vor10/ristandardservice.asmx" to
"http://vao.stsci.edu/directory/ristandardservice.asmx".
The old one will be phased out, and the new one works better, apparently.
I've also changed the name of the constant from "NVO_REG" to "VAO_REG",
since the NVO is more dead than the VAO.

Note @pwdraper and @mmpcn I have also changed both the name and value
of a public static member of splat.vo.SSAPRegistryQuery.  This does
change the public API, but as far as I can tell this constant is never
actually used, so I don't expect it to break anything.