Stop the process with an error message.

@param [err] {Error} - the error instance
@param [options] {object}
@param [options.exitCode] {number} - defaults to 1
@param [options.stack] {boolean} - defaults to false
@static
function halt (err, options) {
  options = Object.assign({ exitCode: 1 }, options)
  if (err) {
    if (err.code === 'EPIPE') {
      process.exit(0) /* no big deal */
    } else {
      const t = require('typical')
      printError(t.isString(err) ? err : options.stack ? err.stack : err.message, options)
    }
  }
  process.exit(options.exitCode)
}