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
* </p>
	 * 
	 * @param destination
	 *            the destination container
	 * @param sourceStores
	 *            the source IFileStore
	 * @return an error message, or <code>null</code> if the path is valid
	 */
	private String validateImportDestinationInternal(IContainer destination,
			IFileStore[] sourceStores) {
		if (!isAccessible(destination)) {
			return IDEWorkbenchMessages.CopyFilesAndFoldersOperation_destinationAccessError;
		}
		String destinationMessage = validateDestinationLocation(destination);
		if (destinationMessage != null) {
			return destinationMessage;
		}
		IFileStore destinationStore;
		try {
			destinationStore = EFS.getStore(destination.getLocationURI());
		} catch (CoreException exception) {
			IDEWorkbenchPlugin.log(exception.getLocalizedMessage(), exception);
			return NLS
					.bind(
							IDEWorkbenchMessages.CopyFilesAndFoldersOperation_internalError,
							exception.getLocalizedMessage());
		}
		for (int i = 0; i < sourceStores.length; i++) {
			IFileStore sourceStore = sourceStores[i];
			IFileStore sourceParentStore = sourceStore.getParent();