ElevationFunction refactored to Distribution (preparing shape-based elevation), polynomial distribution factorized
Moved SVG viewer to a dedicated package, subclassing SVGViewer according to ≠ concerns
refactoring propagated
PDF viewer now statically linked to SVG ones (as a class parameter)
documentation for SVG viewer and ice
heatmap implemented
AssignElevation refactored as a trait, DistributeElevation defined
initial re-implementation of AssignElevation, using polynomial expressions
process elevation defined as assignment or distribution
test + doc
Merge branch 'feature/elevation-shapes' into develop