Improve the dmrpp parser
Found that the dmrpp parser is taking a fair amount of time that can probably be improved. Right now the parser takes and stores the xml attributes, makes a value using the attribute name and the prefix, and then puts those values back into the xml_attrs. A lot of time is spent just copying these values from one place to the other.
To improve this (and hopefully cutback time) I think that we can check to see if the attribute name is already present, if it is then we return a pointer to that attribute rather than go through and find it. If it is not found then we return NULL.