Bug 21672: Switch templates to Bootstrap grid: Various

Bug 21672: Switch templates to Bootstrap grid: Various

This patch modifies various templates to add or improve coverage of the
Bootstrap grid.

To test, apply the patch and view the following pages, confirming that
they look correct at various browser widths:

 - Administration -> Item circulation alerts
 - Authorities -> Authorities search -> Merge records
 - Catalog -> Bibliographic details -> Rota (StockRotation must be
   enabled)
 - Tools -> News: Main and add/edit view

Signed-off-by: Claire Gravely <claire.gravely@bsz-bw.de>
Signed-off-by: Katrin Fischer <katrin.fischer.83@web.de>
Signed-off-by: Nick Clemens <nick@bywatersolutions.com>