Changed title of DEVELOPMENT section to CONTRIBUTION in README.txt
Small changes to setup.py and MANIFEST.in

setup.cfg and INSTALL.txt no longer included in MANIFEST.in

added the following to setup_args dictionary:
zip_safe = False,
license = "BSD, see LICENSE.txt"
Edited version of python in classifiers in setup.py
(changed 2.5 to 2.6 and 2.7)
Merge branch 'master' of https://github.com/diffpy/diffpy.utils