- Explicitly moving the files breaks them, because the wrappers
reference the files by absolute path. Also this automatically
moves the manpages to $dev as well.
- Need to explicitly set --exec-prefix since the pkgconfig file has
`toolsdir=${exec_prefix}/bin`, breaking totem:
http://hydra.nixos.org/build/34980617/nixlog/1/raw
````
checking for BACKEND_TEST... yes
checking GStreamer 1.0 inspection tool... no
configure: error:
Cannot find required GStreamer-1.0 tool 'gst-inspect-1.0'.
It should be part of gstreamer-1_0-utils. Please install it.
builder for ‘/nix/store/npq2ihlsdniv4j3wbyparq9byjxqdi15-totem-3.18.1.drv’ failed with exit code 1
````
While at it, enable parallel build.