Fix nested iteration in a different way
Fix nested iteration in a different way

The previous solution broke adding plugins during a `with` loop.
I considered special casing the `bootstrap` hook but decided that
changing the iterator implementation at the cost of `break` and
`continue` no longer working correctly might be a better solution, as
the behavior would be consistent.

CakeDC/cakephp,ndm2/cakephp,cakephp/cakephp,ADmad/cakephp,ADmad/cakephp,dakota/cakephp,CakeDC/cakephp,dakota/cakephp,mvdriel/cakephp,cakephp/cakephp,ndm2/cakephp,cakephp/cakephp,ndm2/cakephp,mvdriel/cakephp,ADmad/cakephp,mvdriel/cakephp,ADmad/cakephp,CakeDC/cakephp,dakota/cakephp,ndm2/cakephp,mvdriel/cakephp,CakeDC/cakephp,cakephp/cakephp,dakota/cakephp