Unmodified import of octavemagic (and tests) from ipython

The canonical repository is avilable here:
https://github.com/ipython/ipython

octavemagic.py is from 617a629
test_octavemagic.py is from 99483a2
ipython-COPYING.txt is a copy of COPYING.txt from 5901fcd (Reflow license file and
update with link to Github IPython org page.)

These files are the result of much work on the part of the IPython team, and
were available under the terms of the IPython license, also copied here as
ipython-COPYING.txt
Switch test to use local octavemagic