Add Formatters for specific Tasks

[veewee]

As mentioned in #14, the Task::run() method can be very large if custom formatting is added.
Therefor a Formatter interface will be available. It will look something like this:

interface Formatter 
{
    public function formatErrorMessage($output);
    public function formatSuccessMessage($output);
}

The implementation could also format success / error messages to a specific treshold.

[veewee]

Fixed in #142