Also fixes 16314: XML: extractvalue() crash if vertical bar
xml.result, xml.test:
Adding test case
item_xmlfunc.cc:
Using root element as a context node,
instead of NULL, with relative paths.
libmysqld/Makefile.am:
sql/Makefile.am:
Adding new source files.
Adding new file into build process.
include/my_xml.h:
strings/xml.c:
Adding new XML parse flags to skip text normalization and
to use relative tag names. Adding enum for XML token types.
sql/lex.h:
Making parser aware of new SQL functions.
sqll/item_create.h, sql/item_create.cc:
Adding creators for ExtractValue and UpdateXML.
sql/item.h:
Adding new Item types: nodeset and nodeset comparator.
sql/item_xmlfunc.h
sql/item_xmlfunc.cc
Adding new classes implementing XPath functions.
mysql-test/t/xml.test, mysql-test/r/xml.result:
New files: adding test case
