Version response compatible with Folsom

This change adds <link> elements to the <version id="v2.0">
element in the version response to be compatible with the
response given by the Keystone server in the Folsom release.

Fixes bug 1187101

Change-Id: Ida71e2dbe3cf432d429fb739e68a83d7e009ca40
Merge "Version response compatible with Folsom"