[DF-962] add pageLoaded event into UIWebViewDelegate
[DF-962] implement page load  for mac os and ios
[DF-962] add isRedirectedByMouseClick flag into delegate arguments
[DF-962] small refactoring
Merge pull request #162 from adebt/DF-962_WebView

[DF-962] add isInitiatedByUser flag to event openURL & new event: pageLoaded