Merge branch '4.6' of scm.dev.nokia.troll.no:qt/qt-s60-public into 4.6-integration

Merge branch '4.6' of scm.dev.nokia.troll.no:qt/qt-s60-public into 4.6-integration

* '4.6' of scm.dev.nokia.troll.no:qt/qt-s60-public:
  Implement QAudioInput::suspend() using CMMFDevSound::Stop()
  Discard buffer pointer when DevSound is stopped
  Suppress overflow errors raised by Symbian DevSound during playback
  Discard empty buffer on call to QAudioOutput::resume()
  Permit QAudioOutput::processedUSecs() to be called immediately after start()
  Discard all DevSound buffers held when QAudioInput::suspend() called
  Fixed buffer overrun in Symbian QAudioInput backend