Add option to ignore path provided

[dhosterman]

Current behavior is that, when a path is provided, that path and all paths below it are checked for the presence of a file and are recursively deleted if a file doesn't exist. There is no way to specify a path and the desire to purge all empty directories beneath it, but not the specified path if it doesn't have a file (only directories) beneath it, resulting in all directories being deleted regardless of their contents.

Add an option to ignore the directory provided as the argument.

[dhosterman]

Resolved with PR: #3