WIP:  Extracting S-Expression Parsing and Processing Code

See #190 

This PR contains reek with the Sexp-processing code removed.  The extracted library is in the sexp_dresser subfolder

The name is TBD. SexpDresser is just a placeholder for a distinct, greppable namespace.

e.g.

```ruby
$: << 'lib'
require 'sexp_dresser/examiner'
source = File.read('lib/sexp_dresser.rb')
# from the source content of a file
SexpDresser::Examiner.new(source).process
# from a directory
SexpDresser::Examiner.from_paths('lib')
```