ZA: handle members interests browser DoesNotExist errors

Should the user attempt to navigate to a url that results in a
DoesNotExist error, error 500 is currently returned. This  commit
results in the browser filter being displayed to allow the user to
navigate to a valid url. Fixes #1555 (Some views of the interests page
cause 500 errors).
ZA: display message if no results are returned in the interests browser
ZA: ensure members interest source view match method is valid

Defaults the match method to absolute should an invalid method be
specificed in the page url.
Merge branch 'members-interests-browser-issue-1555' of git://github.com/geoffkilpin/pombola into geoffkilpin-members-interests-browser-issue-1555
Merge branch 'geoffkilpin-members-interests-browser-issue-1555'