Documentation front matter is outdated

[mdickinson]

The documentation front matter in front.rst needs to be updated: it still refers to the old Enthought address (515 Congress).

[mdickinson]

We should fix this for Traits 6.1.0.

[corranwebster]

What I did for TraitsUI was merge this into the index.rst, putting the license in a "License" section after the table of contents.

This might make the PDF build less pretty, but I think that's OK.