[test][iterators] Fix signed/unsigned comparison warnings in point_iterator test.
[test][iterators] Fix signed/unsigned comparison warnings in segment_iterator test.
[test][algorithms][distance] add test case between linestring and open multipolygon
where the distance is realized between the linestring and an implicit segment of the
multipolygon
[debug] fix operator<< of segment_identifier, now using os
[debug] extend operator<< of segment_ratio, now displaying the real value too
Merge pull request #151 from mkaravel/fix/distance

[test][algorithms][distance] add test case between linestring and open multipolygon...
[index] Add default template parameters in the implementation of is_valid. Remove MPL assert
[core] Add MPL_ASSERT for coordinate dimension > 0
[iterators] Fix the description of closing_iterator<>.