Add tests for the optimization of trailing return statements

This documents current behavior. When #1038 was fixed, we also optimized
away trailing "undefined" and "return undefined", but that is no longer
the case.
Remove reference to never-defined .isUndefined property

This was added in f4a7cca0755b61fe70db0f7dc5b841aec44022ae to fix #1038
for CoffeeScript 1.0.1. `.isUndefined` was removed in
caf3da2f664f65f3aead70a6292385dea18da9ba but this code was never
updated. That actually caused the behavior of this code to change
(trailing `undefined` and `return undefined` statements no longer got
optimized away) when CoffeeScript 1.3.2 was released, but the new
behavior was deemed correct in
https://github.com/jashkenas/coffee-script/issues/1038#issuecomment-14427560.
Fixes issue #3349, prints deprecation warning

This patch fixes issue #3349, by prints deprecation warning for
users who depends on old(<1.7.0) implicit module registration.
Improved coding convention and messages.
Merge pull request #3386 from blmarket/deprecate_warning

Fixes issue #3349, prints deprecation warning
add newlines to end of files
typo: mult-dot => multi-dot
remove editorialisation
Convert README to Markdown
Merge pull request #3393 from christianbundy/markdown-readme

Convert README to Markdown
Delete README
Update README.md
Update README.md
fix cake install; related: #3395, #3393
fix a spell mistake in cakefile
Merge pull request #3401 from sailxjx/master

fix a spell mistake in cakefile
Package with preferGlobal as appropriate for command-line application

Per https://www.npmjs.org/doc/json.html#preferGlobal

> If your package is primarily a command-line application that should be installed globally, then set this value to true to provide a warning if it is installed locally.
>
> It doesn't actually prevent users from installing it locally, but it does help prevent some confusion if it doesn't work as expected.
Merge pull request #3415 from matt-hickford/patch-1

Package with preferGlobal as appropriate for command-line application
Merge pull request #3355 from aroben/kill-isUndefined

Remove reference to never-defined .isUndefined property
fix spell mistake on index.html.js