Update systemview for a new term

* Use sqlite not mysql, so it's easier to set up
* Update docs and readme
* Be smarter about getting the hostname, use platform not subprocess.

@jordane @lucywyman r?
You should probably include it in your own global `.gitignore` rather than putting it in every repo in that case.

You can create a global `.gitignore` with
```bash
$ git config --global core.excludesfile '~/.gitignore'
```

and then anything in `~/.gitignore` will be ignored in every repo :)