Edited Feature: require intellisense doesn't support substrings [970]

For a module named 'node-uuid', when you type:

```
require(
```

you'll get a completion list that shows up, which includes node-uuid. At that point if you type `uuid`, the completion list will disappear because no module *starts* with uuid. We should support filtering down the completion list with all matches anywhere in the module name, not just those that start with the name that was typed.