- The current implementation of the Interrupted Goode Homolosine
  projection emphasizes land area. This is a compliment projection
  that emphasizes ocean area.
- A value of lon0=-160 produces a reasonable real-world map.

This commit adds five new projections to PROJ:

    adams_hemi: Adams Hemisphere in a Square
    adams_wsI:  Adams World in a Square I
    adams_wsII: Adams World in a Square II
    guyou:      Guyou
    peirce_q:   Pierce Quincuncial

The code originates from Gerry Evendens libproject and has been adapted
to work with modern PROJ. To ensure that the modified code works as
intended extensive test data has been created using libproject and
sproj so that no errors occured when porting from libproject to PROJ.
The test data is wrapped in a gie files. All test cases reproduce
results from libproject at the mm level.