update actionVirtualHost in AppController, prompt for 'frontend' and 'backend' domain name
Merge pull request #115 from Quexer69/4.0

update AppController, prompt for 'frontend' and 'backend' domain name
Cloned existing dev environment as base for env-vars environment + added env-vars environment to environments manifest
Added neam/php-app-config as composer dep
Initial version of env-vars environment
Added support for DATABASE_TABLE_PREFIX config var
Tweaked required/expected status of test database configuration