Adds dashboard/upload/upload.go, instead of oddly shoving it as part
of the coordinator/buildongce tool.
And as part of that (in order to compile and test buildongce/create.go
without installing mercurial on this machine), I updated it from
goauth2 to oauth2.
Despite this "just" being a cleanup CL, it took forever because I hit
OAuth2+Cloud Storage+Web UI woes along the way, documented partially
in upload.go. The web UI misled me for a long time. Maybe I shouldn't
have used service accounts, but it does make configuration easier for
upload.go. The buildongce/create.go probably should use them too,
but I can do that later. I'm done cleaning for now.
Change-Id: Icb8e3decb682d3685edffecea2a10fcb4e385e10
Reviewed-on: https://go-review.googlesource.com/2731
Reviewed-by: Andrew Gerrand <adg@golang.org>
Brad Fitzpatrick