Make specs run with `mspec spec`

Previously, the specs were running with the Rubinius::Toolset
loaded in the runtime instead of the one in the local repository.
Failing spec for $LOADED_FEATURES getting restored after create block
Make sure $LOADED_FEATURES gets restored after create block

Previously, a reference to the about-to-be-mutated array was
being stored as the backup to restore from at the end of the block.
Revert "Make specs run with `mspec spec`"

This reverts commit 947ce1d63b30bd76551ca038aad0ee5a70723622.

Using require_relative breaks CI for ruby 1.8.7 (no such method).
CI is currently using an env var to avoid require_relative.
Merge pull request #2 from jemc/master

Make sure $LOADED_FEATURES gets restored after create block.