Bug 2959 - Cache already failed URLs to speedup check-url.pl

Bug 2959 - Cache already failed URLs to speedup check-url.pl

Based on David Schuster improvement patch.

For David:

- To send the output into an HTML file, there is no need to add a
  paramater to this script, just redirect to a file:

  check-url --html --host-prot=http://koha-pro.mylib.org \\
    > /usr/local/koha/koha-tmpl/badurls.html

- If you want as a result a table with alternate rows, use CSS and
  JavaScript. For example, with jQuery (found with google):

  <style type="text/css">
  table {width:400px; border:1px solid blue;}
  .oddrow {background-color:#E5E5E5;}
  </style>
  <script type="text/javascript"
   src="http://code.jquery.com/jquery-latest.min.js"></script>
  <script type="text/javascript">
  $(function(){
    $("table.tiger-stripe tr:even").addClass("oddrow");
  });

Signed-off-by: Galen Charlton <gmcharlt@gmail.com>