[ipython] Add three config files generated by IPython

It must be the IPython version 2.1.
[ipython] Add a 'cw' profile dedicated to CubicWeb.
[ipython] Add an 'image' profile dedicated to image processing.
[ipython] Python script to easily deploy a IPython profile and config

- Install (i.e. create dir and symlink some files) a profile
- Symlink my crentralized IPy config files to a specific profile
- Clean-up a profile (i.e. remove the dedicated profile folder)