[pkg-gnupg-maint] Bug#933712: libassuan-dev: make package fit for cross development

[W. Martin Borgert]

Package: libassuan-dev
Version: 2.5.2-1

IMHO, this package could be Multi-Arch: same, and therefore
support cross development easily, if two changes are made:

1. Leave out host os in a comment in assuan.h:
    "Generated from assuan.h.in by mkheader for <host_os>."
    (src/mkheader.c:233)

2. Rename /usr/bin/libassuan-config to
    /usr/bin/<multiarch_name>-libassuan-config, e.g.
    /usr/bin/arm-linux-gnueabi-libassuan-config.

The latter probably needs a symlink for the native platform
or similar to not break existing build processes.