just a test, nothing done
progressively removing classes based on onika::Vec class template
fixed cmakelists.txt
onika::math::distance now works on element accessors (thanks to
iterator.h) 
vertexDistance specialization works fine also
min edge length cell compare operator compiles. fixed a bug in rbtree
when left and right node ptr types are not equal or different than
size_t.
adjustments made to trees to make it possible to implemnt red-black
trees without modification of user code
first compilable ParaView 4 plugin. Does nothing
building additional wrappers to map VTK data structures views for onika
wrappers for VTK
Writing data array wrappers for VTK
multi compnent vtkDataArrays are now wrapped !
limited to 2-tuples and 3-tuples, need to be generalized to N
generalized tuple array wrappers for any tuple size, thanks to integer
template parameter packs.
ok, so every template recursion to parse tuples could be replaced with a
few lines ... Wooow
vtk_wrappers still ok
suppressing recursive templates to parse tuples when not necessary