reverted class bid back to struct - thanks to Claudio

src/jrd/ext_proto.h

@@ -25,7 +25,7 @@
 #define JRD_EXT_PROTO_H
 
 namespace Jrd {
-	class bid;
+	struct bid;
 	class ExternalFile;
 }
 

src/jrd/jrd_proto.h

@@ -50,7 +50,7 @@ namespace Jrd {
 	class Attachment;
 	class jrd_tra;
 	class blb;
-	class bid;
+	struct bid;
 	class jrd_req;
 	class Service;
 	class BlockingThread;