Bug 2774 - Path to theme is hard-coded in many places

Bug 2774 - Path to theme is hard-coded in many places

This patch corrects serveral more places in the templates where the path
to the prog theme is hard-coded. To test, apply the patch and view the
following cases:

- When a database update is triggered the login page loads login.css.
  This path should be correct. (Reference to wizard.css is removed as
  per Bug 10422).
- The course reserves home page should load datatables-related assets
  correctly.
- Help pages for the Quick spine label creator and the staff client home
  page should show the correct paths where they reference the Koha file
  system.
- The web installer pages should correctly load the Koha logo.
- The label creator "manage" pages (layouts, templates, etc.) should
  correctly load datatables-related assets.

Signed-off-by: Liz Rea <liz@catalyst.net.nz>
Checked all 5 - look good.

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