nixos/xfce: don't set a bloated GST_PLUGIN_PATH
nixos/environment: do not set GST_PLUGIN_SYSTEM_PATH
xfce4-mixer: use wrapper to set GST_PLUGIN_SYSTEM_PATH
ocaml-javalib, ocaml-sawja: removes wrong path to bash in
configure scripts
mpi4py: New package, version 1.3.1
h5py: New package, version 2.3.1
gummiboot/builder: fix timeout setting when unset

The gummiboot-builder.py script is expecting the @timeout@ metavar to be
substituted for either an empty string (in the case where a user has
left the timeout unset) or the actual value set in the system
configuration.

However, the config.boot.loader.gummiboot.timeout option defaults to
'null', and due to the way pkgs.substituteAll works, the substitution
for '@timeout@' is _never_ set to the empty string.  This causes the
builder script to put a bogus line into /boot/loader/loader.conf:

   timeout @timeout@

Fix this by explicitly setting 'timeout' to the empty string when it's
unset in the system configuration.

Signed-off-by: Josh Cartwright <joshc@eso.teric.us>
nixos tested: only build on supportedSystems
release: do not process broken packages, we induce they don't have platforms at all
Update oraclejdk-7 patch version from 65 to 67
mpi4py: Adhere to package description convention
h5py: Adhere to package description convention
ocaml-javalib, ocaml-sawja: uses patchShebangs rather than ad-hoc patches
Removed mysql dependency as it does not pick up the header files on Linux, even when specified explicitly in the config params.
Merge pull request #3965 from ederoyd46/fix-sphinxsearch

Sphinxsearch Linux
Merge pull request #3944 from joshcartwright/gummiboot-timeout-fix

gummiboot/builder: fix timeout setting when unset
Merge pull request #3955 from paulkoerbitz/master

Update oraclejdk-7 patch version from 65 to 67
CImg and WxCam - New Packages #3519

In this commit, I'm including two new softwares
* CImg: A small, simple image toolkit library
* WxCam: a small, simple, wxGTK-based webcam application
require Nix 1.7 for nixpkgs, since we're using antiquotation inside quoted attribute sets
mpi4py: Change description