Incorrect world file name when generating GeoTIFF file

[seisman]

Issue first reported at GenericMappingTools/pygmt#2698 (comment).

gmt psbasemap -R0/10/0/10 -JM10c -Baf > map.ps
gmt psconvert -A -P -W+g map.ps

The commands above produce two files: map.tiff and map.pgw.

The world file map.pgw makes no sense here:

1. The output file is .tiff, so the expected world file extension should be .tfw, not .pgw
2. Since the GeoTIFF file already has the georeference information embedded, a world file seems useless. Perhaps we should delete the world file in this case?

[seisman]

Ping @PaulWessel and @joa-quim for comments on this issue so that we can take the same action in the PyGMT side.

[PaulWessel]

Leaving this to @joa-quim since he wrote that module.

[seisman]

Ping @joa-quim

[joa-quim]

Yes, that .pgw is a mistake. But can't you just ignore it. Apparently it bothered nobody for ~15 years.

[seisman]

Better to fix it if it's a mistake.