first preparations for surf with explicit cdata
added test
refactored encoding of cdata in shader lib

no logic change so far
first prototype with explicit surface shading colors
updated todo
improved mesh/color input=explicit and repaired colormap processing
surf + explicit color: rewrote input syntax.
updated code docs
moved color normalization code to separate file
color input=explicit: reduced overhead of normalized color representation

Now, it contains only the components, not the colorspace.
color input=explicit: added support for shader=flat
color input=explicit: added support for color interpolation during refinement and related patch builders
added tests for shader=interp and explicit colors
mesh plot handler: fixed bug in refine + shading type
Fixed bugs with refine + shader
improved patchplots lib
color input=explicit mathparse
added test reference revs
added test
color input: improved sanity checking.