Bug 20062: Remove support for Internet Explorer 7 in the staff client

Bug 20062: Remove support for Internet Explorer 7 in the staff client

This patch removes JavaScript files which were added to support Internet
Explorer 7. Templates which included the files have been modified
accordingly.

To test, apply the patch and clear your browser cache if necessary.

Perform a catalog search in the staff client and click through to view
one of the search results. The search results navigation menu in the
left-hand sidebar should work correctly.

Signed-off-by: Claire Gravely <claire.gravely@bsz-bw.de>
Signed-off-by: Katrin Fischer <katrin.fischer.83@web.de>
Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>