[Data-modeling] proposed change to two types: /architecture/architectural_firm and /architecture/engineering_firm

[brendan]

I'd like to draw some cleaner lines here.

Both of these types have properties for "partners". It's been pointed  
out that this is probably asserting too much and lacks the time span  
of their tenure.  It just seems more sensible to remove these  
properties and specify a "suggested type"  /business/employer which  
has a property that can encompass these "facts" in a more general  
way.  There's very little data involved, so I can handle migrating the  
links.

brendan