Deferred: Rename master to primary

Closes gh-4828

(cherry picked from a32cf63)

src/deferred.js

@@ -359,39 +359,39 @@ jQuery.extend( {
  resolveContexts = Array( i ),
  resolveValues = slice.call( arguments ),
 
- // the master Deferred
- master = jQuery.Deferred(),
+ // the primary Deferred
+ primary = jQuery.Deferred(),
 
  // subordinate callback factory
  updateFunc = function( i ) {
  return function( value ) {
  resolveContexts[ i ] = this;
  resolveValues[ i ] = arguments.length > 1 ? slice.call( arguments ) : value;
  if ( !( --remaining ) ) {
- master.resolveWith( resolveContexts, resolveValues );
+ primary.resolveWith( resolveContexts, resolveValues );
  }
  };
  };
 
  // Single- and empty arguments are adopted like Promise.resolve
  if ( remaining <= 1 ) {
- adoptValue( singleValue, master.done( updateFunc( i ) ).resolve, master.reject,
+ adoptValue( singleValue, primary.done( updateFunc( i ) ).resolve, primary.reject,
  !remaining );
 
  // Use .then() to unwrap secondary thenables (cf. gh-3000)
- if ( master.state() === "pending" ||
+ if ( primary.state() === "pending" ||
  isFunction( resolveValues[ i ] && resolveValues[ i ].then ) ) {
 
- return master.then();
+ return primary.then();
  }
  }
 
  // Multiple arguments are aggregated like Promise.all array elements
  while ( i-- ) {
- adoptValue( resolveValues[ i ], updateFunc( i ), master.reject );
+ adoptValue( resolveValues[ i ], updateFunc( i ), primary.reject );
  }
 
- return master.promise();
+ return primary.promise();
  }
 } );