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
* Add getSelected/setSelected to core/common.js
* Migrate core to use Blockly.common.getSelected/setSelected instead of Blockly.selected
* Migrate demos to use Blockly.common.getSelected/setSelected instead of Blockly.selected
* Remove Blockly.selected
* Use variable instead of calling common.getSelected() multiple times
* Add accessor for selected on Blockly
* Add renaming record for Blockly.selected -> Blockly.common.getSelected/setSelected