babeltrace: update from 1.2.1 to 1.2.3

cc @bjornfor
anki: update from 2.0.28 to 2.0.29

cc @the-kenny
dmtx: update from 0.7.2 to 0.7.4

cc @7c6f434c
dhcpcd: update from 6.4.3 to 6.4.7
hdparm: fix expression
cantarell_fonts: fixed derivation
giflib: fixed evaluation
Update Pharo VM

- use latest upstream release
- remove all patches as they are now applied upstream
Merge pull request #4274 from DamienCassou/pharo-vm-update

Update Pharo VM
Merge pull request #4305 from vbgl/coq-containers

Working with Coq
Add haskell package wai-util to nixpkgs
nfs-utils: add missing python dependency

nfsiostat is written in python.

python is already in the closure of nfs-utils, so this adds no cost.
isabelle: 2013 -> 2014, plus add darwin support
btrfsprogs: 3.16 -> 3.16.1
drumkv1: update from 0.5.0 to 0.5.1
qtractor: update from 0.6.2 to 0.6.3
samplv1: update from 0.5.0 to 0.5.1
simplescreenrecorder: update from 0.3.0 to 0.3.1
synthv1: update from 0.5.0 to 0.5.1
xf86_input_wacom: update from 0.26.0 to 0.26.1