* almost rewrote BMessageQueue; simplified code, removed over-extensive documentation,

cleanup.
* made BMessageQueue::IsLocked() const - the non-const version is still provided
  for binary compatibility.
* Both BMessageQueue::FindMessage() versions are now thread safe, the queue's BLocker
  is now mutable to allow for this.
* renamed BMessage::link to fQueueLink as the "Message4" implementation uses it.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@14955 a95241bf-73f2-0310-859d-f6bbb57e9c96

src/kits/app/Message.cpp

@@ -476,7 +476,7 @@ BMessage& BMessage::operator=(const BMessage& msg)
 {
 	what = msg.what;
 
-	link = msg.link;
+	fQueueLink = msg.fQueueLink;
 	fTarget = msg.fTarget;
 	fOriginal = msg.fOriginal;
 	fChangeCount = msg.fChangeCount;
@@ -506,7 +506,7 @@ void BMessage::init_data()
 {
 	what = 0;
 
-	link = NULL;
+	fQueueLink = NULL;
 	fTarget = B_NULL_TOKEN;
 	fOriginal = NULL;
 	fChangeCount = 0;