- reorganize dir structure to 
  - tce/ttasim
  - tce/plda-tta
- plda-tta:
  - refactor common code between ttasim and plda-tta
  - implement plda driver hooks
- clEnqueueCopyBuffer:
  - inside the same device 
  - between multiple devices
- proper schedule generation (process the command queue
  as an entity)
- out of order command queues
