unpisi: Use pisi.package module instead of duplicating extraction code

scripts/unpisi

@@ -14,10 +14,7 @@ import os
 import sys
 from zipfile import BadZipfile
 
-import pisi
-from pisi.archive import ArchiveZip, ArchiveTar
-import pisi.context as ctx
-import pisi.util as util
+from pisi.package import Package
 
 def usage(errmsg):
     print """
@@ -38,26 +35,14 @@ def main():
         usage("File %s not found" % sys.argv[1])
 
     try:
-        arc = ArchiveZip(sys.argv[1], 'zip', 'r')
+        package = Package(sys.argv[1])
     except BadZipfile, e:
         print e
         sys.exit(1)
 
-    arc.unpack_files(['files.xml', 'metadata.xml'], '.')
-    arc.unpack_dir('comar', '.')
-
-    archive_name = None
-    if arc.has_file(ctx.const.install_tar_xz):
-        archive_name = ctx.const.install_tar_xz
-        archive_format = "tarxz"
-    elif arc.has_file(ctx.const.install_tar_lzma):
-        archive_name = ctx.const.install_tar_lzma
-        archive_format = "tarlzma"
-
-    if archive_name:
-        tar_file = arc.open(archive_name)
-        tar = ArchiveTar(fileobj=tar_file, arch_type=archive_format)
-        tar.unpack_dir('.')
+    package.extract_pisi_files(".")
+    package.extract_dir("comar", ".")
+    package.extract_install(".")
 
     return 0