Auto activate content assist on '.' fixed #63

This is now implemented, with the following notes:

1. Content assist will only be auto activated in .js files
2. We should consider making this configurable and using a notion of content types (see #147
3. auto activation defaults to 500ms
4. auto activation can be configured using the ui.auto_activation configuration in .scripted.
5. I changed auto activation for the drop-down menus to use this property as well.