Added wrapper_archiver option

To give user a possibility to choose what archiver he can use another
options was introduced for cd32 and archive wrapper modules. This option
will indicate what archiver should be used for compressing the save
state directories.

fs_uae_wrapper/file_archive.py

@@ -112,6 +112,41 @@ class RarArchive(Archive):
         return True
 
 
+class Archivers(object):
+    """Archivers class"""
+    archivers = [{'arch': TarArchive, 'name': 'tar', 'ext': ['tar']},
+                 {'arch': TarGzipArchive, 'name': 'tgz',
+                  'ext': ['tar.gz', 'tgz']},
+                 {'arch': TarBzip2Archive, 'name': 'tar.bz2',
+                  'ext': ['tar.bz2']},
+                 {'arch': TarXzArchive, 'name': 'tar.xz', 'ext': ['tar.xz']},
+                 {'arch': RarArchive, 'name': 'rar', 'ext': ['rar']},
+                 {'arch': SevenZArchive, 'name': '7z', 'ext': ['7z']},
+                 {'arch': ZipArchive, 'name': 'zip', 'ext': ['zip']},
+                 {'arch': LhaArchive, 'name': 'lha', 'ext': ['lha', 'lzh']},
+                 {'arch': LzxArchive, 'name': 'lzx', 'ext': ['lzx']}]
+
+    @classmethod
+    def get(cls, extension):
+        """
+        Get the archive class or None
+        """
+        for arch in cls.archivers:
+            if extension in arch['ext']:
+                return arch['arch']
+        return None
+
+    @classmethod
+    def get_extension_by_name(cls, name):
+        """
+        Get the first defined extension for the archive format
+        """
+        for arch in cls.archivers:
+            if name == arch['name']:
+                return '.' + arch['ext'][0]
+        return None
+
+
 def get_archiver(arch_name):
     """Return right class for provided archive file name"""
 
@@ -122,18 +157,10 @@ def get_archiver(arch_name):
     if result:
         ext = result.groups()[0]
 
-    archivers = {'.tar': TarArchive,
-                 '.tgz': TarGzipArchive,
-                 '.tar.gz': TarGzipArchive,
-                 '.tar.bz2': TarBzip2Archive,
-                 '.tar.xz': TarXzArchive,
-                 '.rar': RarArchive,
-                 '.7z': SevenZArchive,
-                 '.zip': ZipArchive,
-                 '.lha': LhaArchive,
-                 '.lzx': LzxArchive}
+    if ext:
+        ext = ext[1:]
 
-    archiver = archivers.get(ext)
+    archiver = Archivers.get(ext)
     if not archiver:
         sys.stderr.write("Unable find archive type for `%s'\n" % arch_name)
         return None