New geo extraction

See merge request !6

nondimensional gridspacing computation

See merge request !4

fixing array-extraction from sortedPoly. If an already sortedPoly is used, we don't need to check the array annyhow.

fixing extractSidePolys as it needs to split the sides dependent on weather the number of points is even or not

simplifications. this commit is ignoring failing tests. the sortedPoly-algorithm has to be fixed for generic cases