Updated package.json.
Add mocha runner.
Add test dependencies.
Add substance-util as dependency.
Add dev-dependency to substance-document.
Adapted heading test.
Add tests for handling block quotes.
Add codeblock test.
Test for horizontal rules.
Image, link, ordered lists support.
Merge branch 'recursive_descent' of https://github.com/substance/converter into recursive_descent

Conflicts:
	package.json
package.json resolve conflict
Add test for (inline) links.
Merge branch 'recursive_descent' of https://github.com/substance/converter into recursive_descent
Add test for inline code.
Fix typos.
Add test for image.
Fix typos.
Code, CodeBlock, RawBlock.
Initial implementation of an exporter.