Rerun analysis on GBIF datasets

It's been a bit less than a year since we did the [analysis of GBIF licenses](http://peterdesmet.com/posts/analyzing-gbif-data-licenses.html). @timrobertson100 asked me if I could rerun it, so I did. Scope:

* 13802 datasets
* Number of unique licenses in this run: 413
* Number of new ones in this run: 132
* Number of licenses for all runs: 564

I annotated the 132 licenses and merged the results with the datasets. The results of the analysis are included in the repository, but here are two screenshots. There seems to be a some improvement for the occurrence records.

## 2013 results

![old](https://cloud.githubusercontent.com/assets/600993/4811099/1bcb1250-5eb8-11e4-8683-b76e88d9ac26.png)

## 2014 results

![new](https://cloud.githubusercontent.com/assets/600993/4811102/1fbfe46c-5eb8-11e4-8314-5e937cf296b1.png)