Allow configuring implicit code length and set default
Using digest module means it needs to be 'required'
Fixed issue with lists containing subelements

The mapper was breaking the element onto a newline, leaving a solitary
dash. The first element should be left of the same line. Multiple
elements is a little more tricky, as subsequent children should be
indented to ' ' * 4 * indent_level
Use a div block for divs with classes