add faction widget for progressbar

overviewer_core/progressbar.py

@@ -148,6 +148,12 @@ class Percentage(ProgressBarWidget):
     def update(self, pbar):
         return '%3d%%' % pbar.percentage()
 
+class FractionWidget(ProgressBarWidget):
+    def __init__(self, sep=' / '):
+        self.sep = sep
+    def update(self, pbar):
+        return '%2d%s%2d' % (pbar.currval, self.sep, pbar.maxval)
+
 class Bar(ProgressBarWidgetHFill):
     "The bar of progress. It will strech to fill the line."
     def __init__(self, marker='#', left='|', right='|'):