A Lot of fixes for the issues uncovered by Olimpic.
Still at least 1 known issue: sometimes, when we re-add a Surface, some garbage pops up on the screen for a brief split second. Visible in Olimpic.
Introduce 3 types of Surfaces: System, Tree, User
Do not add Screen to the Surface lists.
Fix OutputSurface.resize(): before it couldn't be called mid-render.
Fix issue with Blur / Multiblur apps
A lot of different fixes.
A lot of issues still there:
1) if we only render part of the tree, tree isomorphism will sometimes not work correctly2) when we change Effects that are inside Trees mid-render, even if we detach() the affected parts of the Tree first, for the last frame the new Effects will be used...
New, cleaner way to create/destroy DistortedSurfaces.
Serious regression in StarWars (crashes!). Looks like the Node's internal FBO is being deleted and not re-created in time.
Minor
Simplify yesterday's refactoring.
Major: change of API.
Split DFramebuffer into Framebuffer and Screen; introduce the 'DistortedInputSurface' and 'DistortedOutputSurface' interfaces.