build system cleanups

build system cleanups

- load(qt_module) => load(qt_build_config)
- remove:
  - CONFIG+=module (obsolete)
  - code relating to module version headers (automated now)
  - %mastercontent assignment (automated now)
  - QT_BUILD_*_LIB defines (automated now)
  - pointless QPRO_PWD assignments
  - pointless DEFINES+=QT_MAKEDLL
  - pointless and commented out include and depend paths
  - qmake -project boilerplate

Change-Id: I8f4586403848fe8f2dff4e889b389956ffcdea59
Reviewed-by: Jonas Rabbe <jonas.rabbe@gmail.com>
Reviewed-by: Michael Goddard <michael.goddard@nokia.com>