pack : add support for tar.gz and tar.xz archives.

.linux/bash/module/pack.sh

@@ -1,4 +1,4 @@
-_UNPACK_SUPPORTED=".tar$|.tgz$|.txz$|.zip$|.iso$"
+_UNPACK_SUPPORTED=".tar$|.tgz$|.txz$|.tar.gz$|.tar.xz$|.zip$|.iso$"
 
 # Pack files into desired format.
 # Usage: pack <TARGET.ext> <FILES>
@@ -89,10 +89,10 @@ unpack()
       "7z")
         _unpack_7z "${target}"
         ;;
-      "tgz")
+      "tgz"|"gz")
         _unpack_tgz "${target}"
         ;;
-      "txz")
+      "txz"|"xz")
         _unpack_txz "${target}"
         ;;
       "tar")