Consider using shellcheck for deeper linting on scripts

[Allele Dev]

Shellcheck: http://www.shellcheck.net/ ; https://github.com/koalaman/shellcheck

Also available off-line via CLI: http://hackage.haskell.org/package/ShellCheck-0.3.0

* Requires: haskell-platform

* Pros
    - Provides rather thorough error detection on scripts
* Cons
    - Requires a heavy dependency

Examples of (potential) issues discovered with shellcheck: http://paste.openstack.org/show/73412/

[Dean Troyer (dtroyer)]

We considered this tool and a couple of other ones before investing the time in writing bash8. The Haskell dep here was enough to eliminate it, it just is not worth the overhead for a style checker and we hit 90% of the typical issues fairly quickly.