Added Makefile and updated documentation.

The documentation explains how to setup a test environment. The Makefile helps
to run the django-compositekey test suite.
Added missing --editable to "pip install" commands.
Added *.egg-info.
Merge pull request #18 from inqbus-gmbh/makefile

Added Makefile and updated documentation.
compatibility with linux and mac Makefile ls -1
checkout django 1.4.6-dev
help text for the Makefile (thanks to keimlink)
starting to develop the django-compositekey 1.5 version
starting to develop the django-compositekey 1.5 version
starting to develop the django-compositekey 1.5 version
support for Django 1.5
update some tests from the djangosuite
testing composite key for Django 1.5
test fails in makefile
2.5 unstable