Revert hacks in text rendering code path

Revert hacks in text rendering code path

There are a lot of hacks here and there in Qt trying to align the
text in a correct way which caused regressions to appear once
the default coordinate system changed. We need to remove these
hacks to get a more consistent and maintainable base. This also
fixes the regression introduced by changing the aliased coordinate
system.

Task-number: QTBUG-27667

Change-Id: I620db2ca23b7ff6c912f3a51e86e7e36bbef81f0
Reviewed-by: Samuel Rødal <samuel.rodal@digia.com>