* build-aux/speedo.mk (appimage, git-appimage, this-appimage): New
targets.
(help): Add documentation.
(define SETVARS, define SETVARS_W64): Set environment variables for
cross-compiling only if TARGETOS is w32.
--
The new appimage targets allow building those parts of GnuPG that are
needed for creating an AppImage of gpg.
Differences to a native build are:
* gpgme is not built
* pinentry-qt is built
* documentation of gnupg is not built
GnuPG-bug-id: 5598