Fix last ghastly commit

There are several things wrong with this commit: https://github.com/Tox/Tox-Technical-Report/commit/d699241540f32f9adf2f7c6275c6dfd9f13a674d

1) et is a Latin word, not an abbreviation, so it shouldn't be followed by a full stop.
2) al., however, is an abbreviation of alli and should be followed by a full stop. So, the correct expression is "et al." or "et alii". Certainly not "et. al"
3) By saying it was written by the "Tox Foundation et al.", you hide the real authors whilst giving credit to people who might not even have contributed. This drive possible helpers away and, at the same time, condoles the unethical idea of giving credit to some people simply because they are part of a certain group, even if they haven't really contributed to this specific task.
4) Stating that it was "written by the Tox Foundation" isn't a literal assertion, but rather a figure of speech known as metonymy. On technical reports, such figurative uses, to the point of frivolousness, should be avoided. Straightforwardness and clearness is sought.
5) The "ACS Style Guide: Effective Communication of Scientific Information",as well as other similar works, do not specify the use of an institution as an author and, as such, to conform to the guidelines and stay on the safe side, the formal style should be followed.