src: fix StringBytes::Write if string is external

Signed-off-by: Fedor Indutny <fedor@indutny.com>
node: remove duplicate tickInfo assignment

When process._setupNextTick() was introduced as the means to properly
initialize the mechanism behind process.nextTick() a chunk of code was
left behind that assigned memory to process._tickInfo. This code is no
longer needed.
src: fix spelling mistake

Signed-off-by: Trevor Norris <trev.norris@gmail.com>
readline: fix close event of readline.Interface()

Not removing 'end' listeners for input and output on the 'close' event
resulted in an EventEmitter related memory leak.

This issue also might be reproduced at:
https://github.com/npm/npm/issues/5203

Signed-off-by: Trevor Norris <trev.norris@gmail.com>