Ensure we pass -developer-build to syncqt for -nokia-developer builds

Ensure we pass -developer-build to syncqt for -nokia-developer builds

When the build directory is the install directory, separate modules
should use qtbase as the path for libs, module pris etc.

This fixes the logic in default_pre.prf so that syncqt is called
correctly in these cases.

Change-Id: Ib3798bfd145d3a3e43b9a222af46270245e6c2e6
Reviewed-on: http://codereview.qt.nokia.com/464
Reviewed-by: Qt Sanity Bot <qt_sanity_bot@ovi.com>
Reviewed-by: Marius Storm-Olsen <marius.storm-olsen@nokia.com>
Reviewed-by: Eckhart Koppen <eckhart.koppen@nokia.com>