Reduce the number of results per page
controllers/search: Limit the number of results

This enforces a limit on the number of results which can be returned by
a query to an arbitrary value (50).

Issue #168.
Provide visual indication of limited results

If a search is performed which returns more than 50 results, a warning
is displayed:

    Limited Results - The number of results has been limited for the
    beta version of the website.

Issue #168.
Merge branch 'issue/168'