dynamic action_name option

I have a controller with one single action that delivers different static pages (terms of services etc.). I want to track those pages with different action_name so that I have to set the action name dynamically. I extended ```ImpressionistController#impressionist``` with one additional option ```action_name``` that may be a string or a block. An example for its usage:

```
class WelcomeController < ApplicationController
  impressionist :action_name => Proc.new{|c| c.params[:page]}

  def static
    #render params[:page]
  end
end
```

Might this be interesting for others? I changed the signature of ```ImpressionController::InstanceMethods#impressionist_subapp_filter``` from ```actions = nil, unique_opts = nil```to ```opts = {}```, is there any code out there that rely on this?