Update to ProtoParser 3.1.0. Add preliminary Guava.

PP 3.1.0 is still making its way around the internet but no one is on this branch and I'm moving on tonight.

@swankjesse @danrice-square @adriancole @loganj 

```
[INFO] ------------------------------------------------------------------------
[INFO] Reactor Summary:
[INFO]
[INFO] Wire Protocol Buffers ............................. SUCCESS [0.821s]
[INFO] Wire Protocol Buffer Runtime ...................... SUCCESS [4.230s]
[INFO] Wire Protocol Buffer Compiler ..................... SUCCESS [2.327s]
[INFO] Wire Protocol Buffer Gson Support ................. SUCCESS [1.107s]
[INFO] ------------------------------------------------------------------------
[INFO] BUILD SUCCESS
[INFO] ------------------------------------------------------------------------
[INFO] Total time: 8.621s
[INFO] Finished at: Thu Jan 02 19:06:34 PST 2014
[INFO] Final Memory: 31M/384M
[INFO] ------------------------------------------------------------------------
```