Bug 11035: Replace shortcut plugin jquery.hotkeys.min.js

Bug 11035: Replace shortcut plugin jquery.hotkeys.min.js

To old plugin prevents the upgrade to the latest jquery. By replacing
with openjs' shortcut.js, we have now one less hurdle in upgrading
Koha to latest.

Changes:
- removed jquery.hotkeys.min.js
- added shortcut.js
- modified the related includes (doc-head-close.inc and help-top.inc)
- modified the calls in staff-global.js

Regression test:
1) apply the patch
2) in the intranet, test the shortcuts alt-q, alt-r, alt-u.

These are the only affected functionalities.  There is no new functionality.

Signed-off-by: Kyle M Hall <kyle@bywatersolutions.com>
Signed-off-by: Katrin Fischer <Katrin.Fischer.83@web.de>
Passes all tests and QA script. Tested existing
shortcuts for the search bar tabs on various circulation
related pages.

This uses a Javascript under BSD license, I wonder if it
should be listed in the About>licenses section that we
are using it. As Yui is also BSD I assume the license is
compatible.

+/**
+ * http://www.openjs.com/scripts/events/keyboard_shortcuts/
+ * Version : 2.01.B
+ * By Binny V A
+ * License : BSD
+ */

Signed-off-by: Galen Charlton <gmc@esilibrary.com>
(cherry picked from commit 39830ac023fb2276ed2fee29913a4ba3fdff9feb)
Signed-off-by: Fridolin SOMERS <fridolin.somers@biblibre.com>