Fix parsing of Qt modules .pri files.

Somewhat unsurprisingly, there can be more than one '=' on a line.

Change-Id: I7d45d3230edf5a722f2effa1f988d2b590c8303f
Reviewed-by: Joerg Bornemann <joerg.bornemann@digia.com>
read Qt.core defines from Qt build

We now read the defines needed for Qt.core from the Qt build instead of
calculating them. This also enables us to remove the namespace property
from Qt.core.

Change-Id: I92bb20f3677eb2012a390f93cb2f047c616e7429
Reviewed-by: Christian Kandeler <christian.kandeler@digia.com>