Removed checking for element visibility and non-zero size from IE driver
The method used for scrolling elements into view and getting their
location will no longer check for element visibility and non-zero. This
code has been moved to the call sites of that method.
Fixed unexpected occurrences of UnhandledAlertException after closing
modal dialogs created using showModalDialog() in IE
Fixing .NET alerts tests and adding onbeforeunload page to trigger leave/stay dialog