[#7] Expansion describing setting up parameters on ReportServer

When deploying to ReportServer data driven parameters created in the BIRT
designer don't work. This addition walks through the details of getting
parameters working on ReportServer.

Also moved the document  to its own folder and images in a subfolder.
[#3] Fix type inferece

The way type was inferred was too simplistic and missed a number of
cases. Should be better now.
Merge branch 'master' of github.com:akvo/akvo-reporting