disable tabular basal settings by default; show them with ?showbasalsettings[=true]

@nicolashery or @jh-bate have a look-see please :)

Naming of variables etc. by no means set in stone. Feel free to change.

Expected behavior: no tabular basal settings by default.
If `?showbasalsettings` or `?showbasalsettings=true`, you get the show/hide norgie (NB: before the hash like so http://localhost:3000/?showbasalsettings=true#/patients/11/data)
If `?showbasalsettings=false`, they are disabled again.
Not that it won't work the way you have it, but since later you'll check for the truthiness of `params.showbasalsettings`, this could've been simply written:

```javascript
var params = this.props.queryParams || {};
this.setState(/*...*/);
```

Although I do have a tendency to do things like `var foo = obj.foo || {}` and check for "truthiness" like `if (foo) {}`, I know not everyone likes that :)