Add parameter & value to request for additional vectors

Created by: treadie

say you have:

?a=1&b=2&c=3

as a request, can you please add an additional parameter/value pair to the end and use them as vectors for testing also. ie.

?a=1&b=2&c=3&vector=payload

This should catch any issues where applications are not handling any unused parameters correctly. Obviously as is the case now, the name and value will both be tested.