graphics/gdalcpp: Add gdalcpp 1.3.0

gdalcpp is a C++11 wrapper classes for GDAL/OGR.

These are some small wrapper classes for GDAL offering:

• classes with RAII instead of the arcane cleanup functions in stock GDAL
• works with GDAL 1, 2, and 3
• allows you to write less boilerplate code

The classes are not very complete, they just have the code I needed for various
programs.