Bug 93245 [Dialogs] Error messages show up in two locations in the properties dialog
Force an error message: 1) select a Java project 2) open the properties dialog 3) navigate to Java Compiler>Building 4) enable project specific settings 5) enter a letter into the maximum number of problems field ->the error message shows up at the bottom 6) resize the dialog ->the error message also shows up in the banner
bundles/org.eclipse.jface/src/org/eclipse/jface/preference/PreferencePage.java
if (newMessage.equals(messageText.getText())
					&& newImage == messageImageLabel.getImage())
				return;
			messageImageLabel.setImage(newImage);
			if (newMessage == null)
				messageText.setText("");
			else
				messageText.setText(newMessage);
			if (showingError)
				setMessageColors(JFaceColors.getErrorBackground(messageComposite.getDisplay()));
			else {
				lastMessageText = newMessage;
				setMessageColors(JFaceColors.getBannerBackground(messageComposite.getDisplay()));
			}
		}
		/**
		 * Show and enable the widgets in the message region
		 */
		private void showRegion() {
			messageComposite.setVisible(true);
		}
		/**
		 * Hide the message region and clear out the caches.
		 */
		private void hideRegion() {
			messageComposite.setVisible(false);
			lastMessageText = null;
			lastMessageType = IMessageProvider.NONE;
		}
		/**