The attached patch tidies up the qmake code for configuring the runtime build so that it's consistent on all platforms, and simply requires that the PGADMIN_PYTHON_DIR environment variable points to the Python installation to be used.
Please review, but don't commit, as this change will probably break some of the Jenkins jobs. I'll commit and fix them when the patch has passed review.
(Sidenote: this is part of a larger tidy up/standardisation of the build scripts).
