added `contrib.redirects` and show pages using a fallback middleware. Close #229
Merge branch 'features/redirects' of github.com:fcurella/pythondotorg into fcurella-features/redirects

Conflicts:
	pydotorg/tests/test_context_processors.py
Merge pull request #263 from fcurella/features/redirects

added `contrib.redirects` and show pages using a fallback middleware. Close #229