The Python argparse library has its own strings, which are translatable
via gettext. This gets those sources strings from the library, and
includes them in this project. Since gettext is invoked and configured
in fdroidserver, fdroidserver needs to handle the translations for the
libraries it uses.
The file context lets the translators know which command the string applies
to. It does not have line numbers, since those are less useful, while
causing lots of merge conflicts.