Use cases for 0.11
------------------

- improve performance 

  * incremental caps
  * cleanup caps fields
  * Make miniobject a simple boxed type
  * reverse negotiation with an event

- buffer metadata

  * Handle strides for video
  * express crop, scaling, region of interest, ...
  * Better support for foreign objects such as Cairo, OpenGL, OMX, ...

- make dynamic pipelines easier

  * sticky event propagation
  * newsegment simplifications
  * per-pad time offsets
