QML.xsd -- Quantity Modeling Language schema.
0.01 Jun. 14 2004 - first draft schema
(brian thomas; baba-luu@earthlink.net)
0.02 Jul. 8 2004 - Allow inheriting Q schema to add attributes to their Q's.
The atomic quantity .. a single "value" only
This is an intermediate to restrict PCDATA in quantity except for trivialQuantities