Added several graph operations BFS, RCM, Hilbert space filling, etc. Depends on B40C.
Added performance files for graph operatiosn
Updated graph documentation and resolved issue with RCM ordering
Minor updates to graph performance tests
Added conditional compilation based on B40C support.
Merge pull request #5 from sdalton1/master

Additional graph functionality, BFS, RCM, Hilbert space-filling curves