Add company-mode as git submodule

When you want to use `company-mode` and set the `cabbage-completion-framework` variable, I just get the following error constantly in the `minibuffer`

```
Error running timer `company-idle-begin': (void-function company-pysmell)
```

Update `company-mode` fix this issue.

Maybe it's a good idea to add the `company-mode` as a submodule.