Add method to determine winding order of linear rings
Store rings so exerior is clockwise and interior is counter-clockwise

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.
Pass options to the base class
The `fromParts` factories take geometry instances instead of coords

The MultiLineString case was correct here.  The MultiPoint and MultiPolygon cases should be using the constructor instead of the `fromParts` factories.
KML MultiGeometry may contain other MultiGeometry

As demonstrated in the tests, a MultiGeometry may contain other MultiGeometry nodes.  We can support this with heterogenous GeometryCollection instances - though these are not currently rendered.
Don't invoke interactions if view is not defined
Make View2D-only comments more consistent
Use view2DState in ol.interaction.Drag
Use view2DState in ol.interaction.DragPan
Use view2DState in ol.interaction.DragRotateAndZoom
Use view2DState in ol.interaction.DragRotate
Use view2DState in ol.interaction.TouchPan
Use view2DState in ol.interaction.TouchRotate
Use view2DState in ol.interaction.TouchZoom
Merge pull request #820 from twpayne/use-view2dstate-in-interactions

Use view2DState in interactions
Merge pull request #690 from fredj/layer-options

ol.layer.Layer: default values
Remove ol.MapBrowserEvent#stopOtherInteractions

and check for false/true in the return from handleMapBrowserEvent. Refs #791.
Merge pull request #829 from tschaub/kml

Parse MultiGeometry in KML
Adding a prettier KML example
Update example to use expression parsing