Make Terminal.markers readonly
Make Terminal.markers readonly

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