Fixes 417. Error now shows on nonexstent function.

You now get the error
"Undefined Variable Name 'blarg'."
If you try to run a non-existant command or have a typo in a command, like so:

```
blarg.
```

It's not the best descriptive message, but it's better than what it did before.

Also, While I was trying to diagnose the situation, I noticed some of the xml auto-docs for the methods I was looking at were missing some param fields, so I added them.