Correct template for include/BoostGraph_i.h

[duffee]

The original template for addEdge included a default value in the definition which died with an error that you couldn't redefine the template with a default value

template <typename G>
bool BoostGraph_i<G>::addEdge(int nodeIdSource, int nodeIdSink, double weightVal=1.0) {
   Pair* twoNodes = new Pair(nodeIdSource,nodeIdSink);
   GEdge* thisEdge = new GEdge(twoNodes,weightVal);
   addNode(nodeIdSource);

which was already defined on line 66

 G* boostGraph;     
virtual bool addNode(int nodeId);
virtual bool addEdge(int nodeIdSource, int nodeIdSink, double weightVal);

I changed it to

template <typename G>
bool BoostGraph_i<G>::addEdge(int nodeIdSource, int nodeIdSink, double weightVal) {
  if (! weightVal ) weightVal=1.0;
   Pair* twoNodes = new Pair(nodeIdSource,nodeIdSink);
   GEdge* thisEdge = new GEdge(twoNodes,weightVal);
   addNode(nodeIdSource);

I am uncertain whether this is the correct way to assign a default. Need to read some docs to see if it causes errors in test.
What is certain is that this does not permit setting a weight of 0 (but why are you adding an edge if you're not going to use it?)