* implemented most of the requriements for decision networks

* fixed decision optimization

* made tests for reliable to random orders in sets

* renamed decision example

* added docstring for add method

Fix change_node_name bug

Make PRIMO compatible to networkx 2

changed the use of networkx to now be compatible to both 1.x and 2.x versions. Also added a small monkey patch so that networkx 1 will still use iterator versions of functions instead of the list versions. Adresses #20

Only add edges in factor Tree when node is connected in BN

added a check as to net create edges in the factor tree to nodes that where not connected in original bayes network, fixes #21

Changing values of nodes

Allow relativ loading of dbn networks from conf

Change node name