Import sniff from PHPCS to fix it.

The current 1.4.x and 1.5.x have a problem with the constant sniff where
trait methods with visibility are flagged as bad constants. Make a local
copy to fix the issue.
Update UpperCaseConstantNameSniff to ignore trait methods

Trait methods that have visibility and names changed should not trigger
errors.
Change coding standards to match the rest of the repo.
Bump version number + add changelog