Fixes memory leak in EN_addnode() (#455)

* Fixing memory leak in EN_addnode()

* Separating test_net_builder from test_toolkit

Making test_net_builder a standalone test

* Removing BOOST_TEST_MAIN

* Work in progress

src/project.c

@@ -401,7 +401,7 @@ void freedata(Project *pr)
     // Free memory for node data
     if (pr->network.Node != NULL)
     {
-        for (j = 0; j <= pr->parser.MaxNodes; j++)
+        for (j = 1; j <= pr->parser.MaxNodes; j++)
         {
             // Free memory used for demand category list
             demand = pr->network.Node[j].D;