allow to start URLs with offset

see https://www.w3.org/TR/media-frags/

cplay.py

@@ -218,6 +218,9 @@ def _play(self):
     def play(self, path):
         self.path = path
         self.position = 0
+        if path.startswith('http') and '#t=' in path:
+            _, offset = path.split('#t=', 1)
+            self.position = float(offset)
         self.length = 0
         self._seek_step = 0
         self._play()