* fixed: InterceptedGrammarHOW needs to be class, not role, so subclasses can override but still call superclass methods
* factor out method &onRegexExit into InterceptedGrammarHOW
* fixed helper RemoteControl.lines: STDIN gets echoed to STDOUT, but you can still get only the lines on STDIN
* improved tests: same coverage but less assertions by using is_deeply more often; using is(...) rather than is .., ...; so we can easily append some || diag "foo".