2011: the 2011/ maps

The 2011/ maps as master held them at 1d02f67. They left the tree in v1.0.0, which put the
newest quarter at latest/; this release keeps them downloadable.

Each zip holds one format and resolution, with the paths as they were under 2011/
(<format>/<level>/<resolution>/...); a -full zip holds the files that sat in no resolution
directory, and extras.zip anything outside geojson/ and topojson/. SHA256SUMS covers them.