* test/xsdtest/xsdtest.xml uri.c: after and exchange with James
  Clark it appeared I had bug in URI parsing code ...
* relaxng.c include/libxml/relaxng.h: completely revamped error
  reporting to not loose message from optional parts.
* xmllint.c: added timing for RNG validation steps
* result/relaxng/*: updated the result, all error messages changed
Daniel