Bug 25363: Merge common.js with staff-global.js

Bug 25363: Merge common.js with staff-global.js

This patch merges the contents of common.js with staff-global.js. Both
are included globally in the staff interface, and there doesn't seem to
be any reason to require that the user downloads two different
JavaScript files.

To test, apply the patch and perform a catalog search in the staff
client.

View the detail page for a title in the search results. On the detail
page you should see navigation controls in the sidebar for browsing
through search results. Confirm they work correctly.

Signed-off-by: Lucas Gass <lucas@bywatersolutions.com>
Signed-off-by: Katrin Fischer <katrin.fischer.83@web.de>
Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>