Clean-up for TNEAGraph

Includes changes such as:
- Implement Load/Save/Dump
- Attr[Name/Value][N/E]I functions debugged and fixed
- Style fixes
Add Jure's benchmarking code to codebase
Lots of small style changes to TNEAGraph

Part of cleanup process.
Merge branch 'master' of github.com:snap-stanford/snapr