tar: support for tar --numeric-owner. By Natanael Copa.

function                                             old     new   delta
tar_longopts                                         221     237     +16
data_extract_all                                     692     705     +13
tar_main                                             690     702     +12

include/unarchive.h

@@ -11,6 +11,7 @@ PUSH_AND_SET_FUNCTION_VISIBILITY_TO_HIDDEN
 #define ARCHIVE_EXTRACT_NEWER           16
 #define ARCHIVE_NOPRESERVE_OWN          32
 #define ARCHIVE_NOPRESERVE_PERM         64
+#define ARCHIVE_NUMERIC_OWNER           128
 
 typedef struct file_header_t {
 	char *name;