title: a new thread for running a cell in ipython/jupyter notebook
body: <p>Sometimes it takes a long time to run a single cell, while it is running, I would like to write and run other cells in the same notebook, accessing the variables in the same context. </p>
  
  <p>Is there any ipython magic that can be used such that when it is added to a cell, running the cell will automatically create a new thread and run with shared global data in the notebook?</p>