Instead of putthing them in the wrong place and then pointing alog at it
via default config, put them in the right place and don't touch the
default config.
- added gnupg to checkInputs
- generate manpage (optional)
- move alot.desktop file to $out/share/applications
- disabled tests as they need the network (dependency on twisted)
Thanks to Sarah Brofeldt, Ben Mcginnes for their help (and other) and
to FRidh for the repeated careful reviews.
