DynamicPositionProperty and DynamicVertexPositionsProperty cleanup

1. Remove `getValueCartographic`
2. Rename `getValueCartesian` to getValue.
3. Remove `getValueRangeCartesian` since it is unused.
4. Also start to clean up DyanmicDirectionsProperty.
Merge branch 'geojson' into dynamicScene-cleanup
Merge branch 'geojson' into dynamicScene-cleanup
Merge branch 'geojson' into dynamicScene-cleanup
Remove getValueSpherical and make it the default result of getValue for DynamicDirectionsProperty.

In reality, I might abandon what I've done so far in favor of a new approach.
Merge branch 'master' into dynamicScene-cleanup
Some boilerplate code for a new property system that's not at all ready yet.
Merge branch 'master' into dynamicScene-cleanup
More Property prototyping.
Merge branch 'master' into dynamicScene-cleanup
greatarc WIP
working EllipsoidGeodesic
Merge branch 'master' into wallGeo
scale wall to surface
fix heights
Start of frustum debug
Merge branch 'master' into wallGeo
Merge remote-tracking branch 'origin/master' into debugfrustum
Initial frustum debug
Merge branch 'batchingdebugcommand' into debugfrustum