Don't generate helper methods when resource's name is Resource

I have troubles when I inherit `ResourcesController` from `InheritedResources::Base`: I try to use `resource_path` or `edit_resource_path` but application gets infinitive recursion and as a result I have exception:

```ruby
SystemStackError - stack level too deep:
  (gem) activesupport-3.2.12/lib/active_support/core_ext/array/extract_options.rb:23:in `'
```

So I see here only one solution - don't define helper methods when resource's class name is "Resource". This fix is about it