pythonPackages.matplotlib: Update to use buildPythonPackage

Matplotlib is currently using hacked together build / install phases
which mimick this functionality of buildPythonPackage. This patch
changes the expression to remove the duplicated build scripting.
network-manager-applet: re-do schema generation

fixes #1355. partial revert of f4d4e12c (introduced by #1313).

meta.priority is set to 6 (lower priority than standard) to resolve the
conflict of an exported gschemas.compiled for evince as for nm-applet.
this linked file is NOT consulted, as both binaries are wrapped to look
for their schemas in their nix store path first.

a better fix would avoid already avoid linking those gschemas.compiled
files into the environment.
add kde-gtk-config-2.2.1
add qtcurve-1.8.17
networkmanager: register PPTP service
networkmanager-pptp: fix checksum
Merge pull request #1452 from ttuegel/networkmanager

Fix networkmanager-pptp
Merge pull request #1416 from wkennington/matplot

Update matplotlib to use buildPythonPackage
Merge pull request #1391 from coroa/nm-applet

network-manager-applet: re-do schema generation
Merge pull request #1443 from ttuegel/kde-gtk-config

add kde-gtk-config-2.2.1
Merge pull request #1444 from ttuegel/qtcurve

add qtcurve-1.8.17
add clementine-1.2.1
add sparsehash-2.0.2
Merge pull request #1453 from ttuegel/clementine

Add clementine-1.2.1 and dependencies
pythonPackages.nose: skip failing test
zsnes seems to work better, without stripping.

I can't understand why. Without disabling stripping, it segfaults
saving state.