Move debian/ directory under doc/

To improve the packaging method under debian, would be nice not to have the debian/ directory under the project root. [Debian developers asked me](http://lists.alioth.debian.org/pipermail/debian-science-maintainers/2014-April/024230.html) about the option of move it to elsewhere. I think than keep a copy inside doc can fix the problem in debian while keeping the easy option for us of generating debs easily (mv doc/debian ../).

The pull request include the rename to 3.4 we did in the 3.4 branch. Feel free to decline it if you plan on merging 3.4 into master.