Add better `inspect` output for ExampleGroup

Pull Request for #1590 

The only problem I ran into was that the syntax error in the after hook test produces error output while running the spec (the test still passes).

> An error occurred in an `after(:context)` hook.
>   NoMethodError: undefined method `expcts' for #<RSpec::ExampleGroups::SomeClass_3 after(:context) hook>

This is definitely not ideal because it could distract from problems with "real" after hooks. The only two options I could up with were: 1) remove the test, or 2) add a way to suppress that error. I'm interested in your thoughts on the best way to handle this.
"it '(no description provided)' is used" isn't really valid English.  This is kind of a pet peeve of mine, but I really like for uses of `it` to read properly.  Mind using one of the following instead?

* `specify '(no description provided) is used' do`
* `it "uses '(no description provided)' instead" do`