X:ActiveModel::Name is not a string in Rails 4, so convert it to string explicitly to cll underscore.

Might be good to encapsulate this in another method so we don't have to change this behavior in >10 places.
Get rid of deprecation warning, match now requires HTTP method to be explicitly set.
Remove deprecation warning by using silence_stream instead of AR::Base#silence.
3.0.2 requirement doesn't let run tests on 3-0-stable and 3-1-stable, so remove it
Use unreleased polyamorous gem with Rails 4 fixes.
Kill some whitespaces.
* Add rails 3.2 context and default context for edge rails
* Add relation_for method to return relation correctly (rails 3.0-3.2 wants #scoped, edge rails wants #all)
Fix deprecation warnings in specs.