* add Line.point_to_t() and tests
* add Arc.point_to_t() and tests
* add a bunch of failing arc/line intersection tests
This commit contains a bunch of failing arc/line intersections that I
and other people have run into.
All these tests are fixed in the following commit.
* better implementation of Arc.intersect(Line)
Fixesmathandy/svgpathtools#35.
This commit fixes all the arc/line intersection test cases added in the
previous commit.
This implementation provides special handling in Arc.intersect() when
`self` is a non-rotated Arc and `other_seg` is a Line. In this case
it uses the straight-forward closed-form solution to identify the
intersection points.
Rotated Arcs and Arcs intersecting with non-Line objects still use
the pre-existing intersection code, that part is totally untouched by
this commit.