WIP
Add ex-62 for bug556
Merge remote-tracking branch 'origin/master' into bug556
Pull out URI normalizing

(raptor_uri_normalize_path): Added and called from
raptor_uri_resolve_uri_reference().

(raptor_uri_resolve_uri_reference): Malloc path_buffer for
hierarchical ref, non-hierarchical base case and copy over, then
normalize.
Handle normalizing reference URIs

Fixes Issue #0000556
http://bugs.librdf.org/mantis/view.php?id=556
Make raptor_uri_normalize_path internal
Normalize file URIs

(raptor_uri_filename_to_uri_string): Use raptor_uri_normalize_path to
normalize the resulting URI
(raptor_uri_resolve_uri_reference): Handle empty ref path
remove dead condition