Resorted Shoreline into class heirarchy
WIP ShorelineWFS
Intersect should re-index if it's never been indexed
Only hit WFS server if a point was specified
Specify version to WFS call, tests pass
Improve starting point on land exception text
Add minimal docs
Merge pull request #4 from daf/shoreline_wfs

Shoreline refactor, add support for WFS backed Shoreline classes