Allow defining SDL framework dir in config_user.pri. Also don't use the default Qt include and library directories when using a specific SDK package, because that would mess with the include paths (frameworks in the SDK will include the wrong headers).
Mac: Further qmake config tweaks
Allow defining SDL framework dir in config_user.pri.
Also don't use the default Qt include and library
directories when using a specific SDK package, because
that would mess with the include paths (frameworks in the
SDK will include the wrong headers).