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
*            the destination container
	 * @param sourceNames
	 *            the source file names
	 * @return an error message, or <code>null</code> if the path is valid
	 */
	public String validateImportDestination(IContainer destination,
			String[] sourceNames) {
		IFileStore[] stores = new IFileStore[sourceNames.length];
		for (int i = 0; i < sourceNames.length; i++) {
			IFileStore store = IDEResourceInfoUtils
					.getFileStore(sourceNames[i]);
			if (store == null)
				return NLS
						.bind(
								IDEWorkbenchMessages.CopyFilesAndFoldersOperation_infoNotFound,
								sourceNames[i]);
			stores[i] = store;
		}
		return validateImportDestinationInternal(destination, stores);
	}
	/**
	 * Checks whether the destination is valid for copying the source file
	 * stores.
	 * <p>
	 * Note this method is for internal use only. It is not API.
	 * </p>
	 * <p>
	 * TODO Bug 117804. This method has been renamed to avoid a bug in the
	 * Eclipse compiler with regards to visibility and type resolution when
	 * linking.