initial draft of container schema chapter & items for discussion

I believe the chapter number is 2, but maybe its 3?

Also, I have 2 additional items to discuss at the meeting:

1 - Will and I think <sim_specs> should be removed as a top-level tag in <xmile> and simply be an attribute of the <model>.  When simulating, the <sim_specs> of the root model would be used, and optionally <sim_specs> specified on modules's models would be honored.  This seems like the cleanest approach to us.

2 - Currently the x & y attributes of stocks have different meanings when width & height are specified.  Without an explicit width/height, x & y refer to the center of the ent, but with width/height specified, x & y refer to the top left corner of the ent.  This is unintuitive, and would make hand-editing a stock display tag a surprising process.  I propose having x/y on all ents refer to the center of the symbol, which allows a more graceful handling of width/height modifications and style cascading.

See you at the meeting.

yours,
Bobby