Test and document the running of all tests inside of nettests/manipulation and nettests/blocking

Some of the tests are documented and tested, while other are not documented and not fully tested.

The documentation for a test should look like this:

https://ooni.readthedocs.org/en/latest/tests/template.html

Look at the links on the main page to see which ones are documented or not.

We should re-run through all of them and figure out what bugs they have.

The ones that perform connections over Tor, have most difficulties because of https://trac.torproject.org/projects/tor/ticket/7269, so for the moment let's not look at them.

I would also look at the output of a test run and see if it looks good and makes sense.

It may be good to first do this: https://trac.torproject.org/projects/tor/ticket/7601