Represents a command call

@param {String} name The name of the command
@param {String} args The arguments to the command
@param {BlockManager} manager The block manager
@param {Number} line The line number
function CommandStatement(name, args, manager, line) {
    this.name = name;
    this.args = args;

    if (!commands[name]) throw new SyntaxError('Unknown command: ' + name);
    this.command = new commands[name](args, manager.create(line));
}