fix indices in explanation
remove helper variables as lists have readable names now
use more readable names for edges (distances)
improve comments & output
simplify code for determining shorter edge
merge handling of remainders into main loop

by checking the length of both lists the case of one list having just its last
entry can be merged into the main while-loop by always removing the first
element of the other list - no special treatment / postprocessing is necessary
anymore
rename remove_first_last() to cut_extrema(), return cut elements
check if start and end of pointlists match
collect triangles in addition to edges