Rewrite and activate message passing by area. Passing by area works now with

the new sematic of transfer_area so a message area is transfered into the right
teams' address space and it does not need to be cloned there anymore. Passing
by area is only used for messages bigger than a certain size (currently
hardcoded to 40KB) which should be somehow bound to the max port message size.
This makes passing large messages (i.e. > the port limit) possible, so for
example copy&paste of long text, image data, etc. should now work.
Got rid of the fClonedArea member as it is not necessary with the new design,
renamed shared_area to message_area in the private message_header, avoid
an unnecessary allocation of the header for the copy constructors, check
allocations in a few more places and some minor cleanup.

git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@24321 a95241bf-73f2-0310-859d-f6bbb57e9c96

headers/os/app/Message.h

@@ -257,7 +257,7 @@ class BMessage {
 		friend class Private;
 		friend class BMessageQueue;
 
-		status_t		_InitCommon();
+		status_t		_InitCommon(bool initHeader);
 		status_t		_InitHeader();
 		status_t		_Clear();
 
@@ -284,14 +284,13 @@ class BMessage {
 		message_header*	fHeader;
 		field_header*	fFields;
 		uint8*			fData;
-		area_id			fClonedArea;
 
 		mutable	BMessage* fOriginal;
 
 		BMessage*		fQueueLink;
 			// fQueueLink is used by BMessageQueue to build a linked list
 
-		uint32			fReserved[10];
+		uint32			fReserved[11];
 
 						// deprecated
 						BMessage(BMessage *message);

headers/private/app/MessagePrivate.h

@@ -68,7 +68,7 @@ struct BMessage::message_header {
 
 	int32		target;
 	int32		current_specifier;
-	area_id		shared_area;
+	area_id		message_area;
 
 	// reply info
 	port_id		reply_port;