Merge changes I0e90b3f3,Ib7769bde,I4c25f34f,I1ec6400a into jb-mr2-dev

* changes:
  implement display projection clipping in h/w composer
  refactor the crop region for hwc is calculated/set
  apply the projection's viewport to the visibleregion passed to hwc
  set correct crop rectangle in LayerBase::setCrop