Bug 9424: Move JavaScript out of header include

Bug 9424: Move JavaScript out of header include

This patch removes JavaScript "onlick" attributes from header.inc and
moves the functionality to staff-global.js. This is in keeping with the
idea of progressive enhancement.

To test, be sure to clear your browser cache after applying the patch.

- Test the help link.
- Test the logout link with the intranetbookbag preference on and off.
- Open a patron's account and click "search to hold." Log out, and log
  in again. Koha should not remember the patron you chose before
  logging out (as seen from a search results page).

Signed-off-by: Galen Charlton <gmc@esilibrary.com>
Signed-off-by: Jonathan Druart <jonathan.druart@biblibre.com>
Signed-off-by: Galen Charlton <gmc@esilibrary.com>