add version information for non python packages

[iamashwin99]

We are trying to create tutorials for a scientific calculation tool written in Fortran called octopus along with a python package called postopus on jupyter notebooks. In order to be able to reproduce the tutorial, its ideal to add the information of the version of octopus and postopus used. The magic command. %version_information postopus is quite useful to this extent.

The issue here concerns extending the %version_information extension to also version non-python executables like octopus . Octopus responds to octopus --version, and so do most other binaries, and adding this interface could be very handy.

To distinguish between a python package and a system package, maybe we can require a character like ! before the package name.