add ability to have the bubbletip disappear when you mouse off the origin element, rather than ALSO including the bubbletip itself

[GoogleCodeExporter]

What steps will reproduce the problem?
1. on the demo page, hove to product bubbletip then quickly move mouse over the 
bubbletip itself. You have clearly left the item that produced the tip and in 
some cases it is desirable for the tip to go away at this time.



What version of the product are you using? On what operating system?
1.0.6 windows 7 firefox, IE and chrome

Please provide any additional information below.
I agree that in many cases, they way it works now is desirable, however, 
including an option to allow it to work the way stated above should be a very 
minimal amount of work.

Original issue reported on code.google.com by chough...@guardian.com on 9 Feb 2012 at 6:51