[COOKBOOKS] Added symlinked proxy hack

 - Rather than backporting CHEF-3307, we add a hack here to make versioned cookbook work
 - When cookbooks_dir attempts to upload a versioned cookbook, it will:
   (1) Create a temporary directory
   (2) Symlink a canonical cookbook name to the versioned cookbook. ( /tmp/x -> /path/cookbooks/x-1.0.0 )
   (3) Upload the proxy
   (4) Remove the temporary directory

This makes the versioned cookbook compatible with Chef 11-stable and 10-stable.