Remove @author tags (#5601)

Our files are up to a decade old, and have churned so much, that the initial author of the file no longer has much meaning.

Furthermore, this will encourage developers to post to the developer group, rather than emailing Googlers (usually me) directly.

demos/blockfactory/factory_utils.js

@@ -10,7 +10,6 @@
  * Exporter applications within Blockly Factory. Holds functions to generate
  * block definitions and generator stubs and to create and download files.
  *
- * @author fraser@google.com (Neil Fraser), quachtina96 (Tina Quach), JC-Orozco
  * (Juan Carlos Orozco)
  */
 'use strict';