Transient properties

Attached is a proposal for supporting transient properties.  You may 
recall that in mid-August we decided to make one last push to see if we 
could define transient properties in 2.0 vs relying on public parameters 
[and needing to retrofit in 3.0].  Please review and comment asap as 
there isn't much time to refine this before needing to make the go/no go 
decision for 2.0.   
   -Mike-