Try to fix two HUD main hangs

The main HUD process can hang due to unhandled exceptions, which
occurred in two separate situations:

1. Table window is closed and HUD instance killed before auto-importer
knows about it
2. Sometimes the threading can jam

These changes attempt to counter the effect of race-conditions. The
dictionary key (table name) is properly tested at the beginning of
update/create block, *but* there are two short round-trips to database
before the key is used. While these occur, the HUD instance can vanish
and thus get its key removed from the dictionary.

Also, when Tables.Table() is created, it will be populated on-demand,
and have child attributes only when such are found from the system. The
new table code pulls in data from actual windows. Again, there is a
query involved and while it runs, the table may have vanished. This
ended up as an error in this call:

foo = gtk.gdk.window_foreign_new(table.number)

The object 'table' is valid (not None) but it has been populated only
after actual table window was killed. Therefore it may not have .number
attribute, which raised an AttributeError. Now the presence of
table.number attribute is tested before the object can be sent to
create_HUD().

pyfpdb/HUD_main.py

@@ -122,9 +122,9 @@ class HUD_main(object):
                     m.update_gui(new_hand_id)
                 self.hud_dict[table_name].update(new_hand_id, self.config)
                 self.hud_dict[table_name].reposition_windows()
-                return False
             finally:
                 gtk.gdk.threads_leave()
+            return False
 
         self.hud_dict[table_name] = Hud.Hud(self, table, max, poker_game, self.config, self.db_connection)
         self.hud_dict[table_name].table_name = table_name
@@ -214,7 +214,14 @@ class HUD_main(object):
                 self.db_connection.init_hud_stat_vars( self.hud_dict[temp_key].hud_params['hud_days']
                                                      , self.hud_dict[temp_key].hud_params['h_hud_days'])
                 stat_dict = self.db_connection.get_stats_from_hand(new_hand_id, type, self.hud_dict[temp_key].hud_params, self.hero_ids[site_id])
+                try:
                     self.hud_dict[temp_key].stat_dict = stat_dict
+                except KeyError:    # HUD instance has been killed off, key is stale
+                    sys.stderr.write('hud_dict[%s] was not found\n' % temp_key)
+                    sys.stderr.write('will not send hand\n')
+                    # Unlocks table, copied from end of function
+                    self.db_connection.connection.rollback()
+                    return
                 cards      = self.db_connection.get_cards(new_hand_id)
                 comm_cards = self.db_connection.get_common_cards(new_hand_id)
                 if comm_cards != {}: # stud!
@@ -245,7 +252,12 @@ class HUD_main(object):
                 else:
                     tablewindow.max = max
                     tablewindow.site = site_name
+                    # Test that the table window still exists
+                    if hasattr(tablewindow, 'number'):
                         self.create_HUD(new_hand_id, tablewindow, temp_key, max, poker_game, type, stat_dict, cards)
+                    else:
+                        sys.stderr.write('Table "%s" no longer exists\n', table_name)
+
             self.db_connection.connection.rollback()
 
 if __name__== "__main__":