Gtk UI: Fix listing of big files on Windows (bug 1562)

For files > 2GB, the list store couldn't handle the
long integer values. Fix this by using a different data
type in the ListStore.

Also fixed a bug that used the wrong units when showing
the file size in the main window (use_si_units was 1).

src/gpodder/gtkui/model.py

@@ -34,6 +34,7 @@
 
 import os
 import gtk
+import gobject
 import xml.sax.saxutils
 
 try:
@@ -60,7 +61,7 @@ class EpisodeListModel(gtk.ListStore):
     def __init__(self, on_filter_changed=lambda has_episodes: None):
         gtk.ListStore.__init__(self, str, str, str, object, \
                 str, str, str, str, bool, bool, bool, \
-                int, int, str, bool, bool, bool)
+                gobject.TYPE_INT64, int, str, bool, bool, bool)
 
         # Callback for when the filter / list changes, gets one parameter
         # (has_episodes) that is True if the list has any episodes
@@ -103,7 +104,7 @@ def __init__(self, on_filter_changed=lambda has_episodes: None):
 
     def _format_filesize(self, episode):
         if episode.length > 0:
-            return util.format_filesize(episode.length, 1)
+            return util.format_filesize(episode.length, digits=1)
         else:
             return None