[DynareDev] Dynare internal documentation

I have uploaded to GIT the beginning of an internal documentation for Dynare. It is written in emacs org-mode and export easily to HTML, Latex and PDF. It is located in ./doc/internals/dynare-internals.org

Sébastien is going to include it in the automatic build system of Dynare and it will be automatically updated from GIT on the web site (or maybe rather on the Wiki as it is just the beginning of something).

Please, comment on the format that can surely be improved upon and suggest practical alternatives. Don't hesitate to contribute as well.

Best,

Michel