KML and WKT don't specify a winding order, so we write those out in CW/CCW order (for exterior/interior). GML references ISO 19107 that specifies CCW/CW, so we serialize in that winding order.
Having hand generated all this GML data the first time around, I reserve the right to modify it for the tests.
Add a parser (read/write) for OGC Well-Known-Text (WKT). It deals with
geometries only, not with features, mostly because WKT can only contain a
single geometry (or geometry collection). This can later on be used to
serialize and deserialize geometries in ol3.