simple/test-debugger-repl-utf8 has a tendency to fail and leave behind a stray
process that listens on common.PORT, making later tests fail with EADDRINUSE.
`process.debug_port` is useful for changing debugger port in runtime,
before starting it (via SIGUSR1).
Using `--port=` argument for debugger repl, tests will run debugger
server on a `common.PORT` (as it usually does for any other servers).
`process._debugEnd()` stops debugger and its server.
* debugger: implemented process._debugEnd(), `node debug --port=5858 app.js`
* test: start debugger repl on common.PORT
* fixes#2613
* fixes#2614
It was decided that the performance benefits that isolates offer (faster spin-up
times for worker processes, faster inter-worker communication, possibly a lower
memory footprint) are not actual bottlenecks for most people and do not outweigh
the potential stability issues and intrusive changes to the code base that
first-class support for isolates requires.
Hence, this commit backs out all isolates-related changes.
Good bye, isolates. We hardly knew ye.
* remove useless clearline call at Interface start
* silence after .handleBreak()
* output '\b' if this.stdout is not a tty (debugger)
* add '\b' checks for clearline (test)
* Don't buffer command, before it's execution (repl)
* `quit` command, custom streams for .start, stubbed out test, disable
history repeation for non-tty (debugger)