* [x-pack/ftr] call fatalErrorHandler when functional tests fail
* [kbn/dev-tools/withProcRunner] require a log as the first arg
* [kbn/dev-tools/procRunner] use correct promise, convert to getter
* [x-pack/ftr] avoid race condition that prevents success message logging
When starting the kibana server it is possible for log messages to come
after the server is started, so we added a pause that waits for 5
seconds of logging silence before logging the success message. The
observable used fails to complete though if a log message is never
written AFTER the Kibana server starts. To counter this the observable
is started with `null` so it will always start at least one 5 second
timer and always complete even if there is no log data after Kibana
server starts.
* fix typo
* [kbn-dev-utils/procRunner] try using execa to avoid never-exitting procs
* [kbn-dev-utils/procRunner] don't listen for close event, rely on stdio streams ending
In an attempt to debug random stalls we are seeing in CI, the proc runner will now send SIGKILL if a process does not exit after receiving the standard exit signal it receives (usually SIGTERM). Additionally, if the child process object never emits "close" or "exit" another timeout will trigger an error
