Bug 123496 [IDE] Use operation validation API for IDE actions
We should use the Resources/Core operation validation API in the IDE actions for manipulating resources.
bundles/org.eclipse.ui.ide/extensions/org/eclipse/ui/actions/CopyFilesAndFoldersOperation.java
return null;
	}
	/**
	 * Validates whether the destination location exists. Linked resources
	 * created on undefined path variables have an undefined location.
	 * 
	 * @param destination
	 *            destination container
	 * @return error message or null if destination location is valid (non-<code>null</code>)
	 */
	private String validateDestinationLocation(IContainer destination) {
		IPath destinationLocation = destination.getLocation();
		if (destinationLocation == null) {
			if (destination.isLinked()) {
				return NLS
						.bind(
								IDEWorkbenchMessages.CopyFilesAndFoldersOperation_missingPathVariable,
								destination.getName());
			}
			return NLS
					.bind(
							IDEWorkbenchMessages.CopyFilesAndFoldersOperation_resourceDeleted,
							destination.getName());
		}
		return null;
	}
	/**
	 * Validates that the given source resources can be copied to the
	 * destination as decided by the VCM provider.
	 *