There were a bunch of free-floating methods in spec_helper. They were
pulled over from test/helper, but they shouldn't be there. Move them
into appropriate modules in spec/support. This commit also cleans up the
"should_accept/reject_dummy_class methods in favor of using proper
matchers directly. This commit should probably not get squashed or git
will likely forget that those matcher specs are the same file because of
how much changed.