Add AddressBar class to replace place holder in toolbar.
Adds a QComboBox derived class ready to replace "empty" in the toolbar.
Class is able to emit messages when the user presses enter in a format accepted my QGraphicsMozView's load() slot.
Set cursor position to 0 after updating AddressBar text.
For sites that use long URLs (SessionID, hashes, search params etc.) it makes it hard to read AddressBar on location change.  This returns the cursor position to the beginning of the line so site can be tracked easier.
Initial AddressBar support.
Not the cleanest of implemenations at the moment but works.
Replace temporary address bar with AddressBar in toolbar.
Connect AddressBar to MozView in toolbar constructor.
Modify BrowserView to provide pointer to MozView.
Modify NavigationToolBar to take pointer to BrowserView.