Fixes django-haystack requirements.txt git reference.
Refer to the django-haystack package on PyPI
Fix pysolr at version 3.0.6 from PyPI
Update and fix django-registration version to 1.0, and source from PyPI

NOTE: James Bennett stepped down as maintainer, and we should source this from elsewhere in the future. Refer to djangopackages or github.
Merge branch 'mildmojo-haystack_requirements_fix'