Add support for reading commonly changed config from env vars
Add support for reading commonly changed config from env vars

Also added App.default_locale.

Refs #224
QoboLtd/project-template-cakephp,QoboLtd/project-template-cakephp,QoboLtd/project-template-cakephp,makallio85/fish-diary,makallio85/fish-diary,QoboLtd/project-template-cakephp,QoboLtd/project-template-cakephp,makallio85/fish-diary