Back/forward history menus now won't show duplicated entries and also
navigating with back/forward on pages won't leave you on the same page
as you are actually visiting.
Though this bug was appearing rarely, it was annoying.
This is not normal QtWebKit behaviour, in standard implementation it is
working just fine, but QupZilla is using QWebPage::extension error
pages, and when this error page appears in frame on page (for example in
<iframe>) it duplicates entry in history.
It is now saving webview's url, not url of request (used to have
problems on some pages)
And addition small improvements
- added possibility to open rss feed in new tab with middle click
- middle click on home button loads homepage in new tab
- right click on back/next buttons now show menu instantly (instead of
holding left mouse button to get menu shown)
