patch Charles Bozeman for validation of all the date, time, and duration

* xmlschemastypes.c: patch Charles Bozeman for validation of
  all the date, time, and duration types
* test/schemas/dur_0* result/schemas/dur_0*: associated tests
* configure.in: fixed an error pointed by an user
* xml2-config.in: fixed an error pointed by an user
Daniel
8 files changed