Document addDisposableListener
Document addDisposableListener

Part of #1642

sourcelair/xterm.js,Tyriar/xterm.js,xtermjs/xterm.js,xtermjs/xterm.js,sourcelair/xterm.js,Tyriar/xterm.js,xtermjs/xterm.js,Tyriar/xterm.js,sourcelair/xterm.js,Tyriar/xterm.js,sourcelair/xterm.js,xtermjs/xterm.js,xtermjs/xterm.js,Tyriar/xterm.js