The plugin is now able to handle both types of WebSVN URLs:

- standard URLs, e.g.
  http://example.com/listing.php?repname=MyRepo&path=%2Ftrunk%2F&rev=10&sc=1
- multiview URLs (introduced with 577ff7e) like
  http://example.com/MyRepo/trunk?&rev=10

This commit restores the WebSVN functionality for sites not using the
multiviews functionality (i.e. as thigs were prior to commit
577ff7e).

Fixes #46