Add cleanupCmds option to pkgs.myEnvFun

This option allows the user to specify commands to run when the shell
exits. This can be used to cleanup operations done in `extraCmds'.

Signed-off-by: Moritz Ulrich <moritz@tarn-vedra.de>
ProofGeneral: Workaround for bug #458

"ProofGeneral 4.2 byte-compilation fails with Emacs 24.2.90"
http://proofgeneral.inf.ed.ac.uk/trac/ticket/458
Update spotify to 0.9.0.133.

Signed-off-by: Moritz Ulrich <moritz@tarn-vedra.de>
spyder: new package

Spyder (previously known as Pydee) is a powerful interactive development
environment for the Python language with advanced editing, interactive
testing, debugging and introspection features.

The name Spyder comes from Scientific PYthon Development EnviRonment.
Merge pull request #502 from bjornfor/spyder

spyder: new package
Merge pull request #498 from the-kenny/fix-spotify

Update spotify to 0.9.0.133
Merge pull request #485 from maggesi/proofgeneral_updates

ProofGeneral: Workaround for bug #458
autojump: add bash as buildInput
Merge pull request #464 from the-kenny/my-env-exit-commands

Add cleanupCmds option to pkgs.myEnvFun. The downside is that /bin/sh remains in memory to be able to execute cleanup commands.
Add optional third party support for fullWebDAV.

This follows the directions fom http://wiki.nginx.org/HttpDavModule.
pstree: version bump from 2.33 to 2.36
nginx: Don't fetch the full WebDAV extension unless needed

Signed-off-by: Shea Levy <shea@shealevy.com>
xarchive: add gtk archiver
Merge pull request #504 from modulistic/master

pstree: version bump from 2.33 to 2.36