Kraftwagenrc under version control

This PR finds kraftwagenrc.php in more locations. It also copies a ./src/cnf/kraftwagenrc.php to ./cnf/kraftwagenrc.php

See also #13

Order to look for a kraftwagenrc.php
- KRAFTWAGEN_SOURCE . /
- ***/etc/***
- ~/.drush/
- ***PROJECT_ROOT . /cnf/kraftwagenrc.php***
- PROJECT_ROOT . /kraftwagenrc.php