-setdeg
template: ster?clnt=<name|pass>&com=setdeg&usr=<usr>&<str_1>=<new_deg_1>&<str_2>=...
          Order of query params is important: position of 'com'
          and 'usr' is not important, however updates of degrees
          are performed in the order they appear in the request.
descript: for the specified user, updates the degrees of the
          stereotypes in the query string, to the new degrees.
          Degrees in the query string that cannot be converted
          to numeric (double) will be considered as NULLs when
          updating the DB. If the specified user does not exist,
          or if some stereotypes in the query string are not
          assigned to that user, corresponding degrees will not
          be updated (200 OK will still be returned). If the error
          code 401 is returned then no changes have taken place.
example : ster?clnt=name|pass&com=setdeg&usr=0.34&visitor=0.85&expert=1.0
returns : 200 OK, 401 (fail, request error), 501 (fail, server error)
200 OK  : in this case the response body is as follows
          <?xml version="1.0"?>
          <?xml-stylesheet type="text/xsl" href="/resp_xsl/rows.xsl"?>
          <result>
          <row><num_of_rows>number of relevant rows</num_of_rows></row>
          </result>
comments: the reference to the xsl file allows to view results
          in a web browser. In case the response body is handled
          directly by an application and not by a browser, this
          reference to xsl can be ignored.