First try to convert the Stencil app to a dual (directly to Screen / through intermediate Framebuffer) mode.Doesn't work yet ( API is inconvenient / plain wrong )
Mipmap levels!
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.
FBO APP: add dynamic adding/removing the DEPTH attachment.