Re: [libvirt] PATCH: Misc error handling / OOM fixes

I ran the OOM checking test suite again and uncovered a handful of pretty minor bugs - no crashers in real code - just forgetting to report OOM correctly * src/datatypes.c: Convert to use the virReportErrorHelper macro instead of a static function, so we get correct function/line number info * src/domain_conf.c: Fix OOM handling in virXPathNodeSet() call so it reports OOM error, instead of ignoring * src/nodeinfo.c: Use _(...) for error message strings * src/xend_internal.c: Add missing check of virBufferError() func and report OOM error * tests/sexpr2xmltest.c: Reset error object between tests, free capabilities object, don't unref a NULL connection object * tests/testutils.c: Fix crash in OOM testing if single threaded * tests/xml2sexprtest.c: Reset error object between tests