Bug 17468: Remove koha-*-zebra scripts and its traces

Bug 17468: Remove koha-*-zebra scripts and its traces

This patch removes traces from the (deprecated) koha-*-zebra scripts.

To test:
- Apply the patch
- Verify no traces of koha-*-zebra remain on the codebase (besides
  Release Notes and the koha-zebra script):
  $ cd kohaclone
  $ git grep koha-start-zebra
  $ git grep koha-stop-zebra
  $ git grep koha-restart-zebra
=> SUCCESS: No traces!
- Create the following symlinks:
  $ sudo ln -s /usr/sbin/koha-zebra  /usr/sbin/koha-start-zebra
  $ sudo ln -s /usr/sbin/koha-zebra  /usr/sbin/koha-stop-zebra
  $ sudo ln -s /usr/sbin/koha-zebra  /usr/sbin/koha-restart-zebra
- Try the koha-*-zebra commands:
  $ sudo koha-stop-zebra kohadev
  $ sudo koha-start-zebra kohadev
  $ sudo koha-restart-zebra kohadev
=> SUCCESS: They all work as expected!

- Sign off :-D!

Sponsored-by: Orex Digital
Signed-off-by: Kyle M Hall <kyle@bywatersolutions.com>
Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>