Moved attribution function to functions.r
Moved ancillary charts into another file
Imported religion data from NHGSI
Use the list of data frames
Refactor shapefile loading

In the Rakefile, define a rule for generating the shapefiles, and generate the
list automatically.

In load-sp.r, load all the shapefiles and fortify them into a list. Change the
other files to access the shapefile data via the list. Cache the shapefile
list into a single file.
Committing the shapefiles