Start extraction to strategy classes
Extract value and directives
Push filter_unsupported_directives to strategies
Push translate_inline_or_eval to strategies
Push implementation specific directives down
Remove #supports_standard?, no longer needed
Move method down with rest of private methods
Remove some refactoring comments
Remove unnecessary explicit return
Try to fix normalize reporting endpoint

Still not happy with this, trying to find a way to push down
into strategies
Simply META attr_accessors
Don't use string appending to build value
Use string interpolation for configure
Move directive? into firefox strategy
Flip overly verbose .nil? checks
Fully qualify namespace for constants in strategy
Merge remote-tracking branch 'b/content_security_policy_refactor'