Merge remote-tracking branch \'toybox/master\' into HEAD

Merge remote-tracking branch \'toybox/master\' into HEAD
am: b9cc6c6427

* commit 'b9cc6c64274a1b67546ff8be78dbc0290b3e0634':
  Start of shell tests: $(()) and $'' expansion.
  Replace list_working with just list, "make list list_pending" shows combined list.
  ps and top are implemented from the android todo. Record enh's wishlist items.
  Dust off toysh, remove ancient config debris, add start of prompt logic.
  Fix tail -NUM again.
  Fix "ssh top".
  Fix top -b.
  Rename gratuitous references to Roger Zelazny's amber series, add comments.
  Fix a buffer overflow in diff -r.
  Andy Chu pointed out an out of bounds access for zero length lines.
  sed -f - should read from stdin.
  Didn't check in all my local basename_r->getbasename changes. (Oops.)
  Jakob Flierl pointed out a broken URL in the README.
  Redefining basename_r to mean something random seems popular (bionic and freebsd both did it) so use getbasename instead.
  Whitespace and comment.
  Implement mv -n / cp -n (no clobber).

Change-Id: I2acb9b1a9a6fa74247a4b6cdd39610853c54e2d3