Move existing smartdown plugins to new proposed directory structure

from:

example_plugin.rb

to:

example_plugin
	- render_time.rb
	- build_time.rb

All of the existing plugins are render time.
Return a hash of plugin types from the plugin factory

Currently just build_type and render_type plugins
as they are the two different types required by
the new Flow API.
Fix for the animal-example-simple flow

Inconsistency between question_1 and question_4,
must have been broken in a merge.
Add Country Question presenter to smartdown adapter
Include a country question in the simple animal example.
Documentation for usage of Data Partials
Bump smartdown version, country questions now work.
Merge pull request #1296 from alphagov/country_questions

Country questions