Cleanup and translations.

I have finished some translation on previous articles, but have let a few of them untranslated in French, as they were part of an old series of demonstrations for school which are not that interesting as standalone articles.

I have however finished a rough translation on a buffer overflow article which is small introductory piece about the topic and should be suitable for beginners. I will be following in that series with more advanced security tutorials when I have some free time. There is also a brief, unstructured article regarding setting up Nagios, but it was mostly an info dump for what I was doing at work.

French translation of project pages will be done at a later time, usually when certain project milestones are met.