TODO_SCHEMAS

- implement counted transitions at the automata level

- Unicode:
  + upgrade to 3.2
  + improve the python script to generate better test
    expressions to check the list of ranges.

- Implement the interface at the SAX level

- Implement the missing parts in the Structure part
   + all content model
   + enumerations
   + countless others c.f. the TODO scattered in the code

- Complete the Built-In datatype collections and Facets implementations

- Regression tests based on
  + the primer:
    http://www.w3.org/TR/xmlschema-0/
  + the Schemas Test Collection:
    http://www.w3.org/2001/05/xmlschema-test-collection/
  + archives of the schemas-dev list

- Integrity constraints:
  + what's that ? How need to read about it

- "formal" checking, i.e. go through the full Structure spec and
  bind code and associated parts of the Schemas spec

- go though the erratas
  http://www.w3.org/2001/05/xmlschema-errata