Use composer instead of PEAR to get codesniffer.
Merge pull request #5293 from ADmad/phpcs-composer

Use composer instead of PEAR to get codesniffer.
Merge branch 'master' of https://github.com/cakephp/cakephp

* 'master' of https://github.com/cakephp/cakephp:
  Use composer instead of PEAR to get codesniffer.