x11/xkeycaps: Update to 2.47

xkeycaps is maintained by a new maintainer, Christoph Berg, a
Debian developer, at https://www.df7cb.de/projects/xkeycaps/. Point
the distfile and WWW URLs to his site.

Update xkeycaps to 2.47. This is the basis of the Debian and other
Linux distros packages. It also resolves a segfault when using the
default CDE font provided by cde-devel.

While at it assume maintainership.