# and ## are broken

[edgarcosta]

https://github.com/sagemath/pari-jupyter/blob/979198caf546910c097fe0afc67017ffc81fa21f/PARIKernel/kernel.pyx#L133=L135

Since the code resets the timer everytime it runs a block, the commands # and ## don't work as expected.

Furthermore, t_ms my be unassigned during a KeyboardInterrupt.