fix type arg of points being used to create lines

[danielfalbo]

Lines require Point<ld>s instead of Point<ll>s

[podd0]

We can shorten the code for dist_point_segnent by removing the pld variable and unnecessary .to_ld()s. Also maybe that function should be in a different file (maybe in line.h) as it's not really about polygons

[danielfalbo]

right! cleaned.

dist_point_segment is used in dist_point_poly, that's why it's in the polygon module probably.

[podd0]

lgtm!