Added xmlXPathCompiledEvalToBoolean() to the API and adjusted/added

* xpath.c: Added xmlXPathCompiledEvalToBoolean() to the API and
  adjusted/added xmlXPathRunEval(), xmlXPathRunStreamEval(),
  xmlXPathCompOpEvalToBoolean(), xmlXPathNodeCollectAndTest()
  to be aware of a boolean result request. The new function
  is now used to evaluate predicates.
3 files changed