Just use the resource name as the dataset name

For combining a data package name and the resource name is just an
unnecessary extra step. This makes everything simpler and easier to
follow.
Fix missing i18n for a few front page strings

A few of the front page strings hadn't been marked as translatable
(prepared for internationalization) and could therefore not be
localized.
Adjust colors on frontpage map

The map was black and white without showing if white or black was
better. Instead of going from black to white, this now goes from
the background color (green) to white. So the more datasets there
are for a given country, the brighter (more apparent) the country
becomes.
Patch version 0.15.5

Improved map on the front page, i18n of a few front page strings
and shorter names for budget data package resources (datasets).