Added Loofah as a dependency in actionview.gemspec. Added Loofah in Gemfile.
Implemented ActionView: FullSanitizer, LinkSanitizer and WhiteListSanitizer in sanitizers.rb
Updated documentation.
Added placeholder for protocol_separator.
Changed implementation of reader/writer methods to be class_attributes and an update_{x} method.
Changed protocol_separator and bad_tags implementation.
Deprecated WhiteListSanitizer instance method protocol_separator.
Updated bad_tags= definition. Removed update_bad_tags.
Deprecated the protocol_separator class attribute.
Deprecated bad_tags class attribute with a long deprecation warning.
Changed the 'update_' methods to class methods.
Removed the protocol_separator class level assignment.
Deprecated instance method protocol_separator.
Updated instance method protocol_separator= deprecation message.
Deprecated instance method bad_tags.
Updated SanitizeHelper to use the updated API in the sanitizers.
Reordered setting of allowed_tags and bad_tags since bad_tags was dependent on allowed_tags.
Removed the require for html-scanner.