TODO:

  + how to cope with time zones? postgres include tz information in results, so,
    how should we use it?

  + make tuples static where possible

  + profile and optimize

  + add database management from inside zope

  + add tests to test suite, check for BINARY (has postgres a binary type?) 
    and for ROWID. 

  + replace all the '-1' (ignored) values in TABLE_DESCRIPTIONS with 
    meaningfull values.

  + convert mxDateTime to DateTime in ZPsycopgDA

DONE:

  + add exceptions to curs_closeall(), curs_commitall(), curs_rollbackall()
    [added asserts]

  + add missing types to the builting type objects

  + write macros to autogenerate types from postgresql headers
 
  + add autocommit
