[algorithms][distance] check distance against 0 only when the minimum
distance is updated
[doc][support status] fix typo: num_interior_rings should have been num_points
[doc][support status] add algorithms is_simple and is_valid
Merge pull request #97 from mkaravel/fix/support_status

Fix/support status
Merge pull request #96 from mkaravel/feature/distance

Optimize distance computations for multi-to-multi and single-to-multi