Bug 3239 - Content-Script-Type and Content-Style-Type

Bug 3239 - Content-Script-Type and Content-Style-Type

This adds headers to define the default script and style languages.
Please note that this output isn't 100% canonical from CGI yet, but
that is due to a bug in CGI:
  http://bugs.koha.org/cgi-bin/bugzilla3/show_bug.cgi?id=3243

So either CGI will perfect it's output, or we can switch to using
HTTP::Headers.  The latter may be desirable anyway, since then we
would not need a CGI $query argument at all.

Signed-off-by: Galen Charlton <galen.charlton@liblime.com>