add link to release notes
Refactor URL rewriting

Use a Markdown extension to hook into the build process and modify the
HTML document tree rather than using regular expressions to process
the HTML.

Fixes #240
Merge pull request #249 from fedelibre/readme-releases

add link to release notes
Move the markdown extension
Add a test case specific to #240
Add a docstring to explain the relative path Markdown extension
Correct a variable name in the tests
Skip dotfiles when copying media

Fixes #245
Merge pull request #250 from d0ugal/script

Refactor URL rewriting
Handle directories starting with a '.'
Remove excessive VWS
Correct method name
Merge pull request #254 from d0ugal/skip-dotfiles

Skip dotfiles when copying media