Update setup.sh to use ruby-install for installing Rubies.
Merge pull request #171 from havenwood/setup

Update setup.sh to use ruby-install for installing Rubies.
Style.
Added RUBY_INSTALL_VERSION.
No need to set RUBIES anymore.
Fix typo in comments.
Match whitespace to current Formula on Homebrew.
Example of non-standard location.

This was the only remaining difference with Homebrew's accepted chruby formula. So now with this change Homebrew's formula is identical to this formula.
Version bump.
Just set RUBY_AUTO_VERSION instead of exporting it (issue #164).

* This will force sub-shells to re-detect .ruby-version and prepend
  ruby to PATH.
Auto-detect rubies using ls (closes #161).
RUBIES must contain absolute paths (issue #161).
Use a find command to avoid empty globs.
Remove the trailing slash.
Update --version short flag to -V instead of -v.
Version bump to 0.4.0.
Also export RUBY_PATCHLEVEL (issue #62).
updated formatting and env descriptions

* Pulled in @HavenWood's chruby man page.
Renamed chruby.md to chruby.1.md.
Moved docs/chruby.1 into share/man/man1/