Bit rot in WebKit browser examples

webkitwidgets\browser:

• Lots of #ifdefs Q_WS_QWS (dead) and Q_WS_MAC (use: Q_OS_OSX or QGuiApplication::platformName() == "cocoa")
• Semi-fishy arguments parsing using QCoreApplication::arguments (should use QCommandLineParser, see fex https://codereview.qt-project.org/#change,81954 )
• Apparently implements some local-server server , could use QLockFile?
• Bookmarks should contain qt.digia.com from start (see fex https://codereview.qt-project.org/#change,79074 )

webkitwidgets\fancybrowser (what is so fancy about this example, btw?)

• Leaks mainwindow
• fishy arguments parsing using argv, should use QCommandLineParser)
• Default URL is Google, should be qt-project.org

Long/mid-term we will have several browser engines , it seems (WebKit, WebEngine, Active X IE and other native engines). It would probably help having some shared code or example for a browser that can use any of them...