Bug 6554 - make Koha internally utf-8 clean

Bug 6554 - make Koha internally utf-8 clean

In current implementation (mostly commented out in this patch)
uses heuristic to guess which strings need decoding from utf-8
to binary representation and doesn't support utf-8 characters
in templates and has problems with utf-8 data from database.

With this changes, Koha perl code always uses utf-8 encoding
correctly. All incomming data from database is allready
correctly marked as utf-8, and decoding of utf8 is required
only from Zebra and XSLT transfers which don't set utf-8 flag
correctly.

For output, standard perl :encoding(utf8) handler is used
so it also removes various "wide character" warnings as side-effect.

Test scenario:
1. make sure that you have utf-8 characters in your biblio
   records, patrons, categories etc.
2. try to search records on intranet and opac which contain
   utf-8 characters
3. install language which has utf-8 characters, e.g. uk-UA
   dpavlin@koha-dev:/srv/koha/misc/translator(bug_6554) $
   PERL5LIB=/srv/koha/ perl translate install uk-UA
4. switch language to uk-UA and verify that templates
   display correctly
5. test search and Z39.50 search and verify that caracters
   are correct

Signed-off-by: Owen Leonard <oleonard@myacpl.org>
I followed the test plan, adding utf-8 characters to library names,
patron categories, titles, and authorized values. I tried the uk-UA
translation and everything looked good.

When performing Z39.50 searches for titles containing utf-8 characters I
got results which were still occasionally contaminated with dummy
characters [?] but I assume this is Z39.50's fault not the patch's.

Signed-off-by: Marcel de Rooy <m.de.rooy@rijksmuseum.nl>
Signed-off-by: Bernardo Gonzalez Kriegel <bgkriegel@gmail.com>
Already signed, add mine.
Signed-off-by: Jared Camins-Esakov <jcamins@cpbibliography.com>