mpd: fix build on darwin
mpdcron: add expression
renpy: update to 6.17.6
seafile: update client, ccnet, libsearpc and shared
qt-5: Don't build tests

Building the tests (which as far as I can tell we don't even run)
makes the build take > 19 GiB of disk space, which is a bit
excessive. Without the tests, it takes 2.6 GiB.
qt-5: Prevent some unnecessary runtime dependencies

The file $out/mkspecs/qconfig.pri contains a list of all include /
library paths used during the build, including build-time-only
packages like GDB and Ruby. So get rid of those.
drumkv1: update from 0.4.1 to 0.4.2
samplv1: update from 0.4.1 to 0.4.2
synthv1: update from 0.4.1 to 0.4.2
update moc
ardour3: 3.5.357 -> 3.5.380 Critical bug fix release
qtractor: update from 0.6.0 to 0.6.1
clementine: disable unfree dependencies by default

Clementine has an optional dependency on libspotify, which is unfree.
Enabling libspotify unconditionally prevented Hydra from distributing
Clementine. Now, we optionally enable it based on
config.clementine.spotify.
basex: update 7.7.2 -> 7.8.2
bcache-tools: update 1.0.5 -> 1.0.7
srecord: update 1.62 -> 1.63
munin: update 2.0.20 -> 2.0.21 (bug fix)
nixos: add 'gvfs' when using GNOME3 desktop

One reason for adding this is to make Chromium able to open files it has
downloaded.

Currently this happens:
  /run/current-system/sw/bin/xdg-open: line 364: gnome-open: command not found

(And nothing happens in the GUI when clicking a downloaded file.)

Looking into xdg-open, one can see that it first tries to run gvfs-open
and then falls back to gnome-open. Adding 'gvfs' makes the first command
succeed.
xca: fix package

For some reason library paths are not set at all for some libraries during
the build. Wrapper with LD_LIBRARY_PATH set for relevant libraries is currently
solution.
weechatDev: 0.4.4dev -> 0.1dev