change output-reporter/formatters

[t4im]

• There's already support for different formats, but no way to decide yet, where it should be formatted to (file? ingame console? formspec? terminal? default:sign?)
• Many report-event handlers still don't know the test outcome, which makes it hard to e.g. implement a TAP formatter for CI systems.
• Formatters could be given the chance to be configurable in appearance
• Despite skipping test steps on success, theres still a lack of "verbosity" control

blocks #13