Make jabber dispatcher configuration works smoothly

[ejhernandez@…]

Jabber dispatcher requires to have a port open within the firewall (if any). The actions to follow are the following:

1. Add 'Jabber dispatcher service' with destination port the one selected by the jabber dispatcher configuration
2. Add an output rule with the jabber dispatcher service as allow

The first action is done if the services module is installed and the second one if the firewall module is also installed.

[ejhernandez@…]

(In [8290]) Added service when it is available with a configuration refs #787

[ejhernandez@…]

(In [8294]) Added position as another index when there is nothing else. Now Jabber dispatcher open the port when it is required closes #787 (spent 3)