bbsengine3.js: use of singleton pattern for the bbsengine instance; polling for notifies and the clock simplified with additional methods; timezone added to clock
getbbsengine() has been changed so that it only creates one instance of the bbsengine object per page.this change is backwards compatible with the old way of returning multiple instances.
added initvisibilityeventhandler(), addinterval(), restartintervals(), and cancelintervals() methods to bbsengine3.js. modified notify.js and clock.js to use addinterval() instead of setting up the event handling per module which meant elimination of a lot of duplicate code. addinterval() checks a boolean to decide if the event handling needs to be set up, so that it is only done once.
the clock now displays an abbreviation for the local time zone of the browser. this is done entirely client side and no polling of my server is done (and anyone is free to use the source if there is a question).