Bug 74529 [Encoding] Encoding on properties no longer explains encoding
I200409212000 This is a regression from previous builds (e.g. 3.0): along with the encoding on the properties dialog there was an explanation where it came from, e.g. inherited from container, detected from file content. This important information has gone.
bundles/org.eclipse.ui.ide/src/org/eclipse/ui/ide/dialogs/AbstractEncodingFieldEditor.java
if (isValidNow != isValid) {
			isValid = isValidNow;
			if (isValid) {
				clearErrorMessage();
			} else {
				showErrorMessage(IDEWorkbenchMessages
						.getString("WorkbenchPreference.unsupportedEncoding")); 
			}
			fireStateChanged(IS_VALID, !isValid, isValid);
			String newValue = getSelectedEncoding();
			if (isValid && !newValue.equals(oldSelectedEncoding)) {
				fireValueChanged(VALUE, oldSelectedEncoding, newValue);
				oldSelectedEncoding = newValue;
			}
		}
	}
	/**
	 * Get the encoding current selected.
	 * @return String
	 */
	protected String getSelectedEncoding() {
		if (defaultEncodingButton.getSelection()) {
			return defaultEnc;
		}
		return encodingCombo.getText();
	}
	private boolean isEncodingValid() {
		return defaultEncodingButton.getSelection() || isValidEncoding(encodingCombo.getText());
	}
	private boolean isValidEncoding(String enc) {