[IPython-dev] Documenting the recent editor sync extension

[Vivian De Smedt]

Hi Fernando,

I have add some end user documentation in the ipy_syncrhonize_with 
module and to the docs\source\interactive\extension_api.txt doc.

I also merge the latest modification of the trunk into they 
synchronize_with branch.

It should be now ready for review ;-)

Regards,
Vivian.