-addftrgrp
template: commu?clnt=<name|pass>&com=addftrgrp&name=<name>&usrs=<name1|name2|...>&ftrs=<name1|name2|name3|...>
descript: Add a new custom feature group into the database. The parameter name specifies the name of the new feature group.
The parameter users specifies the user that the new group belongs. The users must be given as a set of strings separated
with the character '|'. The parameter is optional and can be ommited. When the parameter does not exists PServer assumes
that has the NULL value and so the feature group belongs to everyone. The parameter ftrs contain the features of the group
and they must be given as a set of strings separated by the character '|'.
example : com=addftrgrp&ftrs=ftr1|ftr2|ftr3|ftr4&usrs=usr1|usr2|usr3&name=custom1
returns : 200 OK, 401 (fail, request error), 501 (fail, server error)
200 OK : no response body exists.