Bug 16922: Add RewriteRule to apache-shared-intranet for dev package installs

Bug 16922: Add RewriteRule to apache-shared-intranet for dev package installs

As a simple alternative to the solution in bug 9949 or just as an
additional measure, this patch adds a rewrite rule for intranet
in order to intercept potential misuse of perl scripts that could be
reached on a dev package install via the cgi-bin/koha scriptalias.

It simply rewrites them to the nonexistent "notfound", resulting in a
regular 404 error.

The rewrite rule does not harm regular installs and is just a little extra
step in securing a dev install. You should have more security measures in
place to secure your staff client.

QA Note: Although a rewrite rule may not be our first choice, this one
rule is more elegant and easier to maintain than e.g. a whole bunch of
aliases.

Note: This patch should have a regular and a dev install signoff.

Test plan:
[1] Make sure that this rewrite rule is inserted in your actual apache
    config via /etc/koha/apache-shared-intranet.conf. Restart Apache.
[2] For regular package installs:
    Try one of the URLs in step 3.
    Verify that your staff client still operates as usual. Test a few
    URLs inside some modules.
[3] For dev installs:
    Try some URLs like below.
    Expect 404 errors only, not 500s. If you do not see a 404, go back!
    /misc/stage_file.pl
    /t/db_dependent/default_search_class.pl
    /installer/data/mysql/updatedatabase.pl
    /Makefile.PL
[4] Do you see an additional directory to add to the regex? Please report.

Signed-off-by: Martin Renvoize <martin.renvoize@ptfs-europe.com>
Signed-off-by: Kyle M Hall <kyle@bywatersolutions.com>
Signed-off-by: Joy Nelson <joy@bywatersolutions.com>