Added DSReferencePlane
Added documentation to DSReferencePlane
Throw an exception when a user tries to create a FreeForm element in the family environment - this should be improved
Implemented DSLevel
Implemented DSFloorType, DSFloor
DSFloor.FromExisting added
DSLevel.FromExisting added
Implemented DSSketchPlane
Implemented DSPlaneReference, added public properties to SketchPlane
Obtain Plane and PlaneReference from a ReferencePlane
Update DS dlls
Merge pull request #866 from junmendoza/ChocoButter

Update DS dlls
Merge branch 'ChocoButter' of https://github.com/ikeough/Dynamo into ChocoButter
Save DSRevitNodes.csproj to fix the build
Merge branch 'ChocoButter' of https://github.com/ikeough/Dynamo into ChocoButter