6.0.0

• [Windows] Cleanup camera on app suspension
  Save/restore scanning state on suspend/resume
• Prevent multiple calls to scanner
  Scanner freezes in IOS if multiple calls to the barcode scanner are made at the same time
• [Windows] Focus fails on multiple taps
• send callbacks on dismissViewControllerAnimated completion
  Changed barcodeScanDone method to use a block, so it sends the
  callbacks to the javascript side when the barcode scanner view
  controller has been completely dismissed.
  It was causing problems with the dialogs plugin if you used a dialog on
  the success or error callback
• Retargeted WinRTBarcodeReader component, deprecated windows8 platform support
  This avoids 8.1 projects build error in VS: MSB3030 Could not copy the file WinRTBarcodeReader.winmd because it was not found
• Adds a windows pre compile/run hook to ensure an arch is specified
  Check that an actual architecture is specified for Windows 10 compile/run to avoid a runtime error