Merge branch '4.7' of scm.dev.nokia.troll.no:qt/oslo-staging-1 into 4.7-integration

Merge branch '4.7' of scm.dev.nokia.troll.no:qt/oslo-staging-1 into 4.7-integration

* '4.7' of scm.dev.nokia.troll.no:qt/oslo-staging-1:
  Make qvfb compile (and work) with libpng 1.5
  Updates to Galician localization
  don't misdetect powermac host systems when determining target arch
  Implementation of QNetworkProxyFactory::systemProxyForQuery() for Symbian
  make sure Option::dir_sep is initialized in time
  don't ignore return code from syncqt
  make qtlibinfix apply to QT_INSTALL_TRANSLATIONS
  clean up platform detection logic
  accept -declarative-debug under unix
  Fix static build on Windows with MinGW.
  fix -enable-stdcall-fixup usage
  don't claim declarative debugging support without having declarative
  installation of translations is now dealt with by translations.pro
  German translation fixes
  fix typo in error messages