BUGS.txt

- readline input which spans multiple lines could be only partially
  erased correctly before being re-echoed by remote shell, leading to
  duplicate text.

- readline *really* wants its prompt to start at the beginning of the line.
  if it doesn't, sometimes it will move it there overwriting remote prompt
  etc. So we should probably make it work that way, and the use readline
  functions to erase local echo.
  for example http://stackoverflow.com/questions/15398742/how-can-i-suppress-readline-to-print-something-and-then-restore-it
  http://stackoverflow.com/questions/1512028/gnu-readline-how-to-clear-the-input-line
  (can be noticed sometimes when using up/down to go through history)

- there is race condition; if the remote sends more text but in two or more
  parts, and first par matches $REMOTE_PS1_RE, the readline will be started
  immedeately without waiting for all text. We should probably remember
  somewhere that we sent more than "\n", and if so, expect more than than
  $PS1. but it will backfire on programs with no output (/bin/true), so make
  sure we only add small delay to collect more data, not block for a long
  time.