[Users] NEW FUNCTIONALITY: add_rr_param() in BRANCH / FAILURE routes

[Bogdan-Andrei Iancu]

Hi,

the add_rr_param() can be new safely called from BRANCH / FAILURE 
routes. The behaviour will be:
    - in BRANCH route - the RR parameters are set only for the current 
branch, so you can have different RR params for each branch
    - in FAILURE route - the RR parameters will be set only for the 
outgoing branch, so during serial forking you may add additional RR 
param function of the new destination.


Additional improvements in the RR module usage:
    -record_route() may take as parameter a string to be appended as RR 
param; pseudo-variables may be used.
    -add_rr_param() and record_route_preset() accepts pseudo_variables 
in parameter.
   

Here is a short example on what can be done with the new functionality:

{
    .....
    record_route(";param1=xxx");
    t_on_branch("1");
    t_on_failure("1");
    .....
    t_relay();
}

branch_route[1] {
    add_rr_param(";param2=yyy");
    .......
}

failure_route[1] {
    add_rr_param(";param3=zzz");
    t_on_branch("0"); #reset
    append_branch( URI_2 );
    t_relay();
}

The output will look like:
     after first relay:  ";param1=xxx;param2=yyy"
     after failure route relay : ";param1=xxx;param3=zzz"


regards,
bogdan