Use bang operator for array methods
Use bang operator for array methods

Part of #1319

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