PSR-2 Compliant App Skeleton

Yeah, I kept `- sh -c "pear install --alldeps cakephp/CakePHP_CodeSniffer"` around because of what you mentioned.
Since the core will be last to get these changes, not sure how we want to handle running the CakePHP+PSR2 (once completed) sniffer, while not messing up the core's CI. Remove it temporarily? Or just leave these types of PRs open until the CakePHP sniffer and core is updated?