Use explicit tests in set_Name/set_value
Use explicit tests in set_Name/set_value

Node type enum is not used as an array index anywhere else; the code is not
very readable and the value of this "optimization" is questionable.

The conditions are arranged so that in all normal cases the first comparison
returns true anyway.

zeux/pugixml,zeux/pugixml,zeux/pugixml,zeux/pugixml