Search gives irrelevant results when input contains spaces

A search for e.g. "Institute of Art" will yield all contacts containing the substrings "institute", "of" or "art" (in any order). Depending on the size of the db, this could be thousands of results. The actual "Institute of Art" will be somewhere in the list, but very difficult to find amid all the irrelevant results.

See http://forum.civicrm.org/index.php/topic,34972
and CRM-15442