Add extensions for literate coffeescript watching.
Add detection for passing the `--literate` option.
Update litcoffee detection regex.

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 coffeescript_spec tests to expect literate.

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

Hopefully I'm doing this line wrapping thing right.
Update runner_spec to include literate tests.

Updated old tests to include both new extensions generally, and also add
a new test to ensure the literate option is set.
Update README.md to list support for more exts.

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