Uninitialized constant Ruote::PP

Hello John,

Since updating ruote-resque to use Ruote::ReceivedError, I'm getting an exception when navigating to the error page in ruote-kit.
Here is the stack trace

```
NameError - uninitialized constant Ruote::PP:
/app/vendor/bundle/ruby/1.9.1/bundler/gems/ruote-2048bc6ad7c6/lib/ruote/util/misc.rb:231:in `pps'
/app/vendor/bundle/ruby/1.9.1/bundler/gems/ruote-kit-f42ad9295767/lib/ruote-kit/views/error.html.haml:50:in `block in singletonclass'
/app/vendor/bundle/ruby/1.9.1/bundler/gems/ruote-kit-f42ad9295767/lib/ruote-kit/views/error.html.haml:65528:in `instance_eval'
/app/vendor/bundle/ruby/1.9.1/bundler/gems/ruote-kit-f42ad9295767/lib/ruote-kit/views/error.html.haml:65528:in `singletonclass'
/app/vendor/bundle/ruby/1.9.1/bundler/gems/ruote-kit-f42ad9295767/lib/ruote-kit/views/error.html.haml:65526:in `__tilt_14442160'
...
```