Fix the navbar text links.

Refs #9758
Remove the version suffix from the page titles.

Refs #9758
Use the logo image as for the main mantidproject site.

Includes css to resize and pad the logo along with a new navbar template
to point the href at the main mantidproject site.
Refs #9758
Merge remote-tracking branch 'origin/bugfix/9758_docs_navbar_links'