Mashup TGF and WHO data

Use The [Global Fund][1] database of funding together with WHO's [Global
Health Observatory Data Repository][2]. API endpoints are:

  /api/stats/diseases.json     # List of diseases
  /api/stats/diseases/:id.json # Funding and death summary

[1]: http://www.theglobalfund.org/
[2]: http://apps.who.int/gho/data/?theme=main