We currently only return the image repository name for imageinfo, which
is not particularly useful, especially since image repositories aren't
accessible via the API. This patch adds meta=filerepoinfo, which will
return a list of repositories and relevant information (like the API URL
for ForeignAPIRepo ones)
Also returns the local repo now, and defaults to "all" in a more useful
fashion.
Change-Id: I1aaed0895d2a0bc224c82e93975ecf6afd8cb6b8