(WIP) Paint property hierarchy approach 1 of 2

(WIP) Paint property hierarchy approach 1 of 2

This patch implements one approach for storing the paint property
hierarchy using axillary lists. This approach has a few downsides:
1) No mapping from layout object to paint property. Because paint needs
to be able to lookup the properties generated during UpdatePaintProperties,
we would need some mechanism to lookup the current property.
2) There are potentially many layouts for just a single paint. Because
it is likely the property generation step will get folded into layout,
we need a design that is cache-friendly and can be updated instead of
actually generated from a complete treewalk after every layout. Updating
the auxiliary vector of paint properties may not be efficient.

approach 2 of 2 forthcoming.