Fix infinite loop on simplification producing already existing segment.

Special case happening with poor quality shapefile when the line shared
between 2 shapes are not exactly the same (not all points shared), the
result of simplifying a segment can be an already existing segment.

Deal also with the case of a very narrow loop, simplified to the same
and unique segment on both sides, if not connected to anything else
this single segment will be removed.
Fix capitalization for name with "d'".

Space is not required between d' and name.
Add more debug messages when a ring is not closed.