Update README.md
Merge remote-tracking branch 'origin/readthedocs'
Fix delta bug that caused excess acceleration.
Fixed bad logic while computing canvas offset
Give the renderer a property of resizability.
Fix center of rotation bug by using focalPoint instead.
Viewport resizing.
Change remaining references of namespace ogs.vgl to vgl
Fixes to vtk viewer test.
Fix vtk related tests.
Code cleanup and jslint fixes.
Merge remote-tracking branch 'origin/layer-support' into next