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.
* Add annotations to files under core/events
* Add annotations to files under core/interfaces
* Add annotations to files under core/keyboard_nav
* Add annotations to files under core/renderers
* Add annotations to files under core/serialization
* Add annotations to files under core/theme
* Add annotations to files under core/toolbox
* Add annotations to files under core/utils
* Add annotations to files under core
* Migrate core/events/workspace_events.js to ES6 const/let
* Migrate core/events/workspace_events.js to goog.module
* Migrate core/events/workspace_events.js to named requires
* clang-format core/events/workspace_events.js
* Update build artifact sizes in check_metadata.sh
* Add comment about root cause of build artifact size change
* Migrate core/events/workspace_events.js to ES6 const/let
* Migrate core/events/workspace_events.js to goog.module
* Migrate core/events/workspace_events.js to named requires
* clang-format core/events/workspace_events.js
* Clarify require name for Blockly.Events.Abstract
