The placeholder text shows "Search or enter web address" which doesn't
tell the user about *how* the search will be performed. Other popular
open source browsers show the search engine that will be used. For
example:
Chromium: "Search **engine** or type a URL"
Firefox: "Search with **engine** or enter address"
This change changes the placeholder text of the location bar to show
"Search with **engine** or enter web address".
The URL is now not shown when a new tab is initially activated until
the location bar loses focus. This allows the user to see the location
bar placeholder text when opening a new tab. It also makes it easier to
paste URLs into the location bar after opening a new tab.
This will help a lot with developing chromes for different UI frameworks
where we can see which helper classes and processes are really using Qt
vs just using it to get at helper data.
As a bonus, remove Qt dependency from WebDriver.
