preliminary truecolor (RGBA 32) support

font rendering and flat shading fully ported
compatibility palette wrapper for the other shading modes
temporarily drop transparent filling (must be reimplemented)
rename for more clarity
introduce the explicit frame structure

Export and polish from the `console' module and move it into the core.
Add and document the new frame APIs.
Adapt the existing APIs.
frames now always have the ZBuffer.
initial wireframing support.
Merge branch 'truecolor'
integration fixes after merge.