Previously, a.js.coffee -> a.js but b.js.litcoffee -> b.js.js.
Assuming that having double .js is useless, we detect the missing case
properly.

Additionally, update the setting of the literate flag, as
`File.extname` only returns the final extension.

Update expected regexes and tests to check .coffee.md and .litcoffee,
with an eye out for improperly escaped period characters.

Hopefully I'm doing this line wrapping thing right.

Updated old tests to include both new extensions generally, and also add
a new test to ensure the literate option is set.

Also, line break on longer lines of options to avoid scrolling in
the fixed width Github readme viewer.