Switched to the heap-using dijkstra code
In SampleFirstKernel: removed dangling extra argument used with the old old (wholly-matlab) version of dijkstra's.
In SampleFirstShortestPathDistribution: switched Sebastien's dijkstra out for dijkstra_heap_m
Renamed dijkstra_heap.m to avoid name clash with dijkstra_heap.mexa64.
In roadData_kernels: removed dangling extra argument to SampleFirstKernel.