Wrap relation calls and scope calls in decorators

* wrap model in decorator when scope is called on decorator
* decorate named scope calls on decorators and enumerable proxies
fix typo with class name
move fake ActiveRecord::Relation to helper, use #kind_of instead of comparing to string
Merge pull request #257 from jhsu/draper-scope-wrap

Wrap relation calls and scope calls in decorators
Decorate struct objects correctly

Struct objects implement #each, but they should not be decorated using
DecoratedEnumerableProxy.
Merge pull request #259 from indrekj/struct-objects

Decorate struct objects correctly
Totally change test integration.

We no longer need to do specific things before tests run. The
view_context now loads up appropriate things if they don't exist.

I ended up getting rid of two spec files; one tested things that
were very simple, but since we're not mocking Rails anymore, they're
much harder to test. The second was the stuff that I removed. :)
Break reliance on ActionController.

Originally brought up in #249, I didn't know how to fix this.

But now I do.
Remove setup from Test::Unit generator
relaxing ammeter dependency version

This means we don't get warnings any more.
Revert "Break reliance on ActionController."

This reverts commit b3a2af7488f76db235a84d993077dbc51fa82cb4.

Basically, we have an issue with ActionMailer::Base. Given this
code, we end up with

```
private method `new' called for ActionMailer::Base:Class
```

And That's Bad (tm).

Still that commit should point the way to making it happen somehow.
Remove #tap.

@reinh points out that this is a bug
Let's actually memoize that, shall we?
Separate ViewContext get/create context behavior

Separating these behaviors eliminates and entire class of bugs like forgetting to re-set the thread local, attempting to re-set the block-local conditionally, and so on. It also makes it more obvious that `self.current` is memoizing.
Merge pull request #264 from reinh/patch-1

Separate ViewContext get/create context behavior
Adds the ability to decorate an enumerable proxy
adding h method to enumerables
tests for decorating enumerable proxy
Merge pull request #265 from stevenbristol/master

Allowing enumerable proxys to be decorated
removing un-needed things for testing