Fixed regression in 45ee253 by checking GEOSisRing first.
Tests for linestring/linearring construction

Test when constructing from LineString and add special checks
for when the line is unclosed
Use GEOSisClosed instead of GEOSisRing when cloning LinearRing from LineString.
Merge pull request #1 from jwass/speedup_linestring_clone

Tests for linestring/linearring construction
Merge pull request #171 from snorfalorpagus/speedup_linestring_clone

Fixed regression in 45ee253 by checking GEOSisRing first.