Move the decode_utf8() call for various feeds to entityize()

Move the decode_utf8() call for various feeds to entityize()

decode_utf8() is special in that it won't transform any string once
its 'utf8' flag has been set, so it is a safe subroutine to call
multiple times for a given string.

As it turns out, SRU (and in turn Z39.50) is suffering from a double-encoding
of the search terms, so we have to forcefully double-decode the terms with
the decode('utf8') variation that does not respect the 'utf8' string.

This will enable Z39.50 and SRU queries to actually return results for
queries like 'Montréal' and 'Québec'. Eventually we need to figure out
where in the SRU/CGI stack the strings are being incorrectly encoded in
the first place, but for now a much-improved Z39.50 server seems acceptable.

git-svn-id: svn://svn.open-ils.org/ILS/trunk@15320 dcc99617-32d9-48b4-a31d-7c20da2025e4