Fix live development connection in Chrome 27 beta

Fix for #3402 

* Change Inspector domain methods to return a promise if no explicit callback parameter is defined
* Force ``Page`` domain to load prior to loading other agents (some agents wait for Page ``loadEventFired`` event...yes the name is from the department of redundancy department)
* Wait for domain ``enable`` calls to complete before agent loading continues
* Misc event handler cleanup

@njx can you retest on mac w/ chrome 27? I've tested mac Chrome 26 and win Chrome 27.