Do not automatically add a \n to all messages formatted by
qFormatLogMessage. Some backends require a final newline,
some don't, so it's best to only append it where it's actually needed.
The returned string will be null if the pattern is empty. This allows
to differentiate between the case that the pattern just didn't apply
(empty line is printed), and the case that qSetMessagePattern(QString())
have been called (nothing is printed).
Change-Id: I17fde997a4074f58f82de6dea129948155c322d6
Reviewed-by: Oswald Buddenhagen <oswald.buddenhagen@theqtcompany.com>
Reviewed-by: Alex Blasche <alexander.blasche@digia.com>