Add option to detect symlinks in cookbookdirs as cookbooks

[Phil Dibowitz]

It would be nice when handling multiple different environments to be able to treat these as changes so they can be detected and uploaded.

[Phil Dibowitz]

• In Changes::Cookbook.initialize we should for each file store if it's a symlink
• Add a config option for want_symlinks_to_count_as_cookbooks
• Then in Changes::Cookbook.meaningful_cookbook_file? if the option is set and it's a symlink and it's in a cookbook dir, return true.

[Mike Dodge]

#74

[Davide Cavalca]

@jaymzh @mikedodge04 is there anything left to do here?

[Phil Dibowitz]

Closed by #74