2.0.0

• 590:
  Added key modifiers to pointer and key events.
• 564:
  Implemented 2.0 event handling API
• 585:
  Deflect proxy: update to Deflect 0.12 v5 API, use new PAN event to move
  camera instead of switching between pan/rotate with TAP_AND_HOLD event,
  handle new pinch event to zoom.
• 584:
  Removed broken CUDA/ComputeContext support
• 578:
  Application command line arguments are transmitted to render clients.
  Subsets of environmental variables can also be transmitted based on their
  prefixes.
• 574:
  Deflect proxy: Consider DEFLECT_ID, use deflect env for render clients
• 572:
  Sequel: Fix crash on exit
• 570:
  Use new Collage launch code