fix($location): prevent infinite digest error due to IE bug

If an app uses HTML5 mode and we open an html5 url on IE8 or 9 which
don't support location href, we use location.replace to reload the page
with the hashbang equivalent of the url but this fails with infinite
digest. This is because location.replace doesn't update location.href
synchronously on IE8 and 9.

Closes #2802, #3305, #1417