-getusrftr or getusr
template: pers?clnt=<name|pass>&com=getusrftr&usr=<usr>&ftr=<ftr_pattern>[&num=
          <num_pattern>&srt=<order_pattern>&cmp=<comp_pattern>]
          Order of query params is not important. Query params
          'num', 'srt', and 'cmp' are optional. If ommited, 'num'
          defaults to '*', 'srt' defaults to 'desc', and 'cmp' to 'n'.
pattern : for feature, * | name[.*], where name is a path expression.
          For num, * | <integer>.
          For srt, asc | desc. For A->Z use 'asc', for 10->1 use 'desc'.
          For cmp, s | n. Values are compared as strings if cmp==s,
          while they are compared as numbers (doubles) if cmp==n.
          String values that cannot be converted to doubles are
          represented as NULLs in numeric comparison.
descript: for the specified user, the features matching the pattern
          are found and sorted according to value (based on 'srt' and
          'cmp'), and secondarily according to feature name (asc, A->Z) .
          Then the first <num_pattern> rows are selected (or all, if
          <num_pattern> is '*') and an XML answer is formed. If no
          feature in DB matches the pattern or if <num_pattern> <=0
          or if user does not exist, the result will not have any
          'row' elements (200 OK will still be returned).
          Note that 'srt' and 'cmp' affect the sorting on value.
          Note that in case a number of features matching the pattern
          have the same value, some of them may be part of the
          results, while others not. This depends on 'num', which
          determines in absolute terms the number of result rows.
          Which of the features with the same value will be part of
          the result depends on the feature name, which is a secondary
          field of ordering.
example : pers?clnt=name|pass&com=getusrftr&usr=john&ftr=lang.*&num=3
          pers?clnt=name|pass&com=getusrftr&usr=152&ftr=page5.*
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/singleuser_profile.xsl"?>
          <result>
              <row><ftr>feature</ftr><val>value</val></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.