[EM] Block group map of Texas

[Raph Frank]

I generated some pdf maps of Texas.

They are pretty big as they include all the lines that are included in
the census data.  They would stress even the best of computers.

However, it shows the kind of shapes that are included in the census system.

County - 1MB (7MB expanded)
http://www.electionsciencefoundation.org/temp_images/county.zip

Tract - 4MB (32MB expanded)
http://www.electionsciencefoundation.org/temp_images/tract.zip

Block Groups - 7MB (60MB expanded)
http://www.electionsciencefoundation.org/temp_images/tract.zip

I also did a block one, but it comes to 420MB.