Bug 11331 - CSV export for viewlog.pl is missing newlines

Bug 11331 - CSV export for viewlog.pl is missing newlines

When you try to export the result of tools/viewlog.pl in csv, file
cannot be correctly loaded :
  - newline is missing after each record,
  - strings should be enclosed in ""
  - columns are not the same as for screen output

This patch corrects this by using like other export Text::CSV.
Adds a header line made with the keys of first data. For that, all data
values are initialiszed with empty string.

Test plan :
- Use a database with some logs, see sysprefs
  /cgi-bin/koha/admin/preferences.pl?tab=logs
- Go to export page /cgi-bin/koha/tools/viewlog.pl
- Select a module
- Click on "To a file" and choose a file name
- Click on "Submit"
- Open file
   => Without this patch : newline is missing, multi-lines cells are not
      enclosed in "", there are no column headings
   => Without this patch : each line is a data line, complexe cells are
      enclosed in "", there are column headings
- Test the export of all modules to see that all headings are necessary
- Check the output to screen in the browser

Signed-off-by: Owen Leonard <oleonard@myacpl.org>
The CSV export is significantly improved. I question the usefulness of
including biblioitemnumber in the output. A better inclusion would be
itemnumber.

Signed-off-by: Katrin Fischer <Katrin.Fischer.83@web.de>
While this feature is still not perfect, this is a big improvement.
Passes tests and QA script, restores basic functionality.

Signed-off-by: Tomas Cohen Arazi <tomascohen@gmail.com>