pythonPackages: add alembic, database migration tool for SQLAlchemy
pythonPackages: add ColanderAlchemy, generator for colander schemas from sqlalchemy models
pythonPackages: add execnet, rapid multi-Python deployment
pythonPackages: add pytest-xdist, plugin for distributed testing and loop-on-failing modes
pythonPackages: add memory_profiler, a module for monitoring memory usage of a python program
pythonPackages.psutil: update to 1.0.1
pythonPackages: add wand, ctypes-based simple MagickWand API binding for Python

Conflicts:
	pkgs/top-level/python-packages.nix
pythonPackages.sqlalchemy: update to 0.8.2
pythonPackages: add sqlalchemy_imageattach, SQLAlchemy extension for attaching images to entity objects
pythonPackages: add pyramid_multiauth, stacked authentication policies for pyramid
pythonPackages: add htmllaundry, simple HTML cleanup utilities
pythonPackages: add statd, client for Etsy's node-js statsd server
pythonPackages.sqlalchemy_imageattach: fix tests
pythonPackages: add sphinxcontrib_http
pythonPackages: add sphinx_pypi_upload