Bug 10782 - Add a koha-mysqlcheck script

This patch adds the koha-mysqlcheck script, as a "frontend" for
the mysqlcheck command. It can be used to check the integrity of
database tables, as well as to repair them. See "man mysqlcheck"
for more information.

The script takes a Koha instance name as its only required
parameter. Any other parameters provided before the instance
name are passed directly to mysqlcheck, which means that all
the functionality of mysqlcheck is available through this script.

To test the script:
- Apply the patch, build your own packages and install them, or
- copy koha-mysqlcheck to a server already running off packages

- Run some variations of the command, with and without arguments,
  and check that the output makes sense. E.g.:
    sudo koha-mysqlcheck myinstance
    sudo koha-mysqlcheck -e myinstance # Extended checks
    sudo koha-mysqlcheck -e -v myinstance # Extended checks and verbose
- See "man mysqlcheck" for other relevant options

To test the man page:
- Run these commands and look at the formatted man page:
    $ xsltproc /usr/share/xml/docbook/stylesheet/docbook-xsl/manpages/docbook.xsl \
      debian/docs/koha-mysqlcheck.xml
    $ man -l koha-mysqlcheck.8
- Make sure this test passes:
    $ prove -v xt/verify-debian-docbook.t

Signed-off-by: Chris Cormack <chris@bigballofwax.co.nz>
Signed-off-by: Martin Renvoize <martin.renvoize@ptfs-europe.com>
Signed-off-by: Galen Charlton <gmc@esilibrary.com>