Bug 15230: Remove unused file circ/stats.pl and stats.tt from system

Bug 15230: Remove unused file circ/stats.pl and stats.tt from system

This patch removes stats.pl and stats.tt from system.

To test:
- Verify that both files are not used and that the only reference in
  koha-tmpl/intranet-tmpl/prog/en/modules/circ/circulation-home.tt
  is commented out.
- Apply patch
- Verify that the files are deleted and the reference is removed.
- git grep 'stats.pl', verify that there are no more references to
  this file.

Signed-off-by: Owen Leonard <oleonard@myacpl.org>
Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>
See the following commit for more info on this script:
  commit 60105bd692a07639f275543365acfca4f464c1a2
  Date:   Tue Jul 8 20:02:34 2008 -0500
    fix for 2008: Daily reconciliation report broken

Signed-off-by: Kyle M Hall <kyle@bywatersolutions.com>