Setting up the baseline tests, creating an appearance identifier,
and basic image-grabbing functionality doesn't need to be reinvented
for each test case that wants to use baseline testing of widget UIs.
As a drive-by, remove unneeded Qt 5 meta tags from .pri file.
Change-Id: I1562e1b377946305cac018e0f0f0175c2c07cd31
Reviewed-by: Eirik Aavitsland <eirik.aavitsland@qt.io>
