adding options to erb scaffold generator to include or skip custom views / templates

created a small patch.. looking for feedback / etc..

https://rails.lighthouseapp.com/projects/8994-ruby-on-rails/tickets/5319-adding-options-to-erb-scaffold-generator-to-include-or-skip-custom-views-templates#ticket-5319-2

When I was working on customizing the erb scaffold generator to match
the style and design I wanted to use by creating custom templates in /
lib/templates/erb/scaffold I found that I wanted to add additional
files.

I can now do something like the following:

$ rails generate scaffold FitType key:string name:string
description:text --add-views=_nav --skip-views=new ...

  invoke erb
  create app/views/fit_types
  create app/views/fit_types/index.html.erb
  create app/views/fit_types/edit.html.erb
  create app/views/fit_types/show.html.erb
  create app/views/fit_types/_form.html.erb
  create app/views/fit_types/_nav.html.erb << extra template ..