Added block level styling hooks for lists, fixes #26

`marked` assumed that the class hook was part of the list item, so this
required a bit of jiggery-pokery to keep the class hook outside.
Added --no-images flag, fixes #25

In case there's a story that doesn't use any image-related features at
all, this flag can prevent apocalism.js from erroring out
bump to 0.4.1