Support lambdas for config values (other than experimental and http_additions)
some cleanup
fix tests from fake apps
goodbye spork and simplecov, tired of you
lol ruby: elsif -> else
Merge branch 'master' into enforce_lambda

Conflicts:
	fixtures/rails_3_2_12/spec/controllers/other_things_controller_spec.rb
	lib/secure_headers/headers/content_security_policy.rb
Merge pull request #97 from twitter/enforce_lambda

Two bug fixes: lambda support for more config values and propegating the default-src value to img-src in one case