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.

core/utils/aria.js

@@ -8,7 +8,6 @@
  * @fileoverview ARIA-related constants and utilities.
  * These methods are not specific to Blockly, and could be factored out into
  * a JavaScript framework such as Closure.
- * @author samelh@google.com (Sam El-Husseini)
  */
 'use strict';
 

core/utils/colour.js

@@ -8,7 +8,6 @@
  * @fileoverview Utility methods for colour manipulation.
  * These methods are not specific to Blockly, and could be factored out into
  * a JavaScript framework such as Closure.
- * @author fraser@google.com (Neil Fraser)
  */
 'use strict';
 

core/utils/coordinate.js

@@ -8,7 +8,6 @@
  * @fileoverview Utility methods for coordinate manipulation.
  * These methods are not specific to Blockly, and could be factored out into
  * a JavaScript framework such as Closure.
- * @author fraser@google.com (Neil Fraser)
  */
 'use strict';
 

core/utils/deprecation.js

@@ -7,7 +7,6 @@
 /**
  * @fileoverview Helper function for warning developers about deprecations.
  * This method is not specific to Blockly.
- * @author fenichel@google.com (Rachel Fenichel)
  */
 'use strict';
 

core/utils/dom.js

@@ -8,7 +8,6 @@
  * @fileoverview Utility methods for DOM manipulation.
  * These methods are not specific to Blockly, and could be factored out into
  * a JavaScript framework such as Closure.
- * @author fraser@google.com (Neil Fraser)
  */
 'use strict';
 

core/utils/global.js

@@ -6,7 +6,6 @@
 
 /**
  * @fileoverview Provides a reference to the global object.
- * @author samelh@google.com (Sam El-Husseini)
  */
 'use strict';
 

core/utils/idgenerator.js

@@ -6,7 +6,6 @@
 
 /**
  * @fileoverview Generators for unique IDs.
- * @author samelh@google.com (Sam El-Husseini)
  */
 'use strict';
 

core/utils/keycodes.js

@@ -8,7 +8,6 @@
  * @fileoverview Constant declarations for common key codes.
  * These methods are not specific to Blockly, and could be factored out into
  * a JavaScript framework such as Closure.
- * @author samelh@google.com (Sam El-Husseini)
  */
 'use strict';
 

core/utils/math.js

@@ -8,7 +8,6 @@
  * @fileoverview Utility methods for math.
  * These methods are not specific to Blockly, and could be factored out into
  * a JavaScript framework such as Closure.
- * @author fraser@google.com (Neil Fraser)
  */
 'use strict';
 

core/utils/metrics.js

@@ -6,7 +6,6 @@
 
 /**
  * @fileoverview Workspace metrics definitions.
- * @author samelh@google.com (Sam El-Husseini)
  */
 'use strict';
 

core/utils/object.js

@@ -6,7 +6,6 @@
 
 /**
  * @fileoverview Utility methods for objects.
- * @author samelh@google.com (Sam El-Husseini)
  */
 'use strict';
 

core/utils/rect.js

@@ -8,7 +8,6 @@
  * @fileoverview Utility methods for rectangle manipulation.
  * These methods are not specific to Blockly, and could be factored out into
  * a JavaScript framework such as Closure.
- * @author fraser@google.com (Neil Fraser)
  */
 'use strict';
 

core/utils/size.js

@@ -8,7 +8,6 @@
  * @fileoverview Utility methods for size calculation.
  * These methods are not specific to Blockly, and could be factored out into
  * a JavaScript framework such as Closure.
- * @author samelh@google.com (Sam El-Husseini)
  */
 'use strict';
 

core/utils/string.js

@@ -8,7 +8,6 @@
  * @fileoverview Utility methods for string manipulation.
  * These methods are not specific to Blockly, and could be factored out into
  * a JavaScript framework such as Closure.
- * @author fraser@google.com (Neil Fraser)
  */
 'use strict';
 

core/utils/style.js

@@ -8,7 +8,6 @@
  * @fileoverview Utilities for element styles.
  * These methods are not specific to Blockly, and could be factored out into
  * a JavaScript framework such as Closure.
- * @author samelh@google.com (Sam El-Husseini)
  */
 'use strict';
 

core/utils/svg.js

@@ -7,7 +7,6 @@
 /**
  * @fileoverview Defines the Svg class. Its constants enumerate
  * all SVG tag names used by Blockly.
- * @author samelh@google.com (Sam El-Husseini)
  */
 'use strict';
 

core/utils/svg_paths.js

@@ -7,7 +7,6 @@
 /**
  * @fileoverview Methods for creating parts of SVG path strings.  See
  * developer.mozilla.org/en-US/docs/Web/SVG/Tutorial/Paths
- * @author fenichel@google.com (Rachel Fenichel)
  */
 'use strict';
 

core/utils/toolbox.js

@@ -6,7 +6,6 @@
 
 /**
  * @fileoverview Utility functions for the toolbox and flyout.
- * @author aschmiedt@google.com (Abby Schmiedt)
  */
 'use strict';
 

core/utils/useragent.js

@@ -8,7 +8,6 @@
  * @fileoverview Useragent detection.
  * These methods are not specific to Blockly, and could be factored out into
  * a JavaScript framework such as Closure.
- * @author fraser@google.com (Neil Fraser)
  */
 'use strict';
 

core/utils/xml.js

@@ -8,7 +8,6 @@
  * @fileoverview XML element manipulation.
  * These methods are not specific to Blockly, and could be factored out into
  * a JavaScript framework such as Closure.
- * @author fraser@google.com (Neil Fraser)
  */
 'use strict';