Expose CreateBrowser() with a callback argument that will be executed after browser was created

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Currently creating browser is possible only with the  synchronous function 
CreateBrowserSync. There are cases for the asynchronous creation to be useful. 
The only drawback is that there is no easy way to get the browser object after 
browser was created. The callback argument would provide a way to get the 
browser object after it was created. The callback will be called with browser 
as the first argument. Currently to get the browser object one would need to 
implement the OnAfterCreated global client callback. But this is not convenient 
to get a specific browser object.

Original issue reported on code.google.com by czarek.t...@gmail.com on 22 Jan 2015 at 8:41