Merge r1516806 from trunk:

 * r1516806
   Do not look at the hostname part of an URI when checking that
   the schema data is canonical.
   Justification:
     As reported on dev@, "svn co file://./" and similar commands abort
     instead of returning an error that the URL is invalid.  This was
     caused by svn_uri_is_canonical treating the hostname "." as a path
     segment.  After this change, svn_uri_is_canonicall correctly
     determines that the URL is (syntactically) canonical, and the
     commands later fail with a normal error in the RA layer, which
     validates the semantics of the hostname.
   Votes:
     +1: brane, stefan2, philip


git-svn-id: https://svn.apache.org/repos/asf/subversion/branches/1.7.x@1540941 13f79535-47bb-0310-9956-ffa450edef68