Preparing the next release

- Define getter and setter for properties with some simple checks
- Remove links when stopping container
- Added test cases for automatic testing
- Replaced False as return value with exceptions based feedback
- Common functionality is provided by decorators
- Added checks if keys are in project.args
- Always fall back to default behavior when an arg is missing in projects.args
- Colored output can be suppressed with a parameter
- Added reboot command
- Extended documentation removed some TODOs/open issues
- Restructured feature wish list in README