Change IBrowserProcess methods to return bool with out param for result to indicate error
Catch and return Exception for TryCallMethod, TryGetProperty, TrySetProperty methods, passed back to the browsersubprocess though currently not displayed in the UI
Create BrowserProcessResponse to represent the response from the WCF calls
Pass BrowserProcessResponse through to JavascriptMethodHandler and JavascriptPropertyHandler so errors can be conveyed back to CEF
Return false when an exception is thrown
Change ExecuteScriptAsync to return JavascriptResponse so error messages and result can be returned
Remove unused code (WaitHandle is no longer required)
Fix whitespace