Update jTimeout.js - close tab across multiple windows when not using jAlert

[jhamsle]

I made the "hideCountdownAlert" function overriddable. This way if someone wants to control their dialog/UI they'll be able to have it close properly across multiple windows. Note: "timeout.timeoutWarning = false;" should still be in the overridden method, or the pop-up won't display again and will continually fire "close" events.