code: function exec(command, fallthrough, cb) {
    execute(command, fallthrough, false, function(err, stdOutOuput, stdErrOuput, result) {
      // drop stdOutOuput and stdErrOuput parameters to keep exec backwards compatible.
      cb(err, result);
    });
  }
docs: Execute a one-liner command.
  
  The output emitted on stderr and stdout of the child process will be written to process.stdout
  and process.stderr of this process.
  
  Fallthrough is handy in situation where there are multiple execs running in sequence/parallel,
  and they all have to be executed regardless of success/error on either one of them.
  
  @param {String} command: command to execute
  @param {Boolean} fallthrough: allow error to be camouflaged as a non-error
  @param {Function} cb: standard cb(err, result) callback