Added options to specify what events PowerTip should listen on
Close any open tooltip when clicking on the page

- Specifically, clicking on an element that does not cause a tooltip to open (with the exception of elements that are within a tooltip that has 'mouseOnToPopup' enabled) closes any open tooltip
Updated readme and examples with 'openEvents' and 'closeEvents' options
Fixed some build errors
Fixed a typo and updated some terminology for consistency
Merge pull request #75 from breity/events

Fixes for #67