Added unit test to verify destroy() API method cleans up open tips
Added unit test to verify destroy() API method cleans up open tips

Ref commit: f4677633331d2767a694deb5a1b5ac198dacedbd
Probably related to issue #165.

jasco/jquery-powertip,stevenbenner/jquery-powertip,stevenbenner/jquery-powertip,jasco/jquery-powertip