Fix PHPCS break
Remove custom LOGS constant replacement
Use upper-case DSN everywhere
Remove extra single quote
Standardize on setting 'username' and 'password' keys

CakePHP users a variety of names for these keys internally, though the most widely recognized are the above, so it makes sense to standardize on them.

Note that we remove the `user` and `pass` key from the $parsed config instead of the $config as it is possible to have them in a querystring argument.
Switch Database and Cache libraries from `login` to `username`

This unifies the name we give to the `username` key across all classes within CakePHP.