This way newly added files will be not be excluded by default. Fixes
also a small whitespace error in utils.py.

Reviewed-by: iustinp

As per Michael's comment, gitignore should not ignore a couple of real
files from the autotools/ directory.

Reviewed-by: ultrotter

This adds a simple diagram for the cluster architecture and also adds a
dependency on graphviz (both doc and in configure).

Reviewed-by: imsnah

The patch adds the apidoc target and the epydoc config file for it. Note
that this is for epydoc 3.0 and that it will put the docs into
./doc/api/.

The patch also adds a new .gitignore rule for the auto-generated rapi
fragment.

Reviewed-by: imsnah

Reviwed-by: imsnah

This makes it easier to setup new git repositories, and makes it more
likely all people have the same ignore rules.

Reviewed-by: imsnah