Added inline field editing for strings and document removal

Another attempt at the update/delete PR I made a while ago, this time with a different approach. It uses one `updateCollection` field in the main settings object which is used to update the given collection.

* Supports virtual fields
* CSS hides the delete button if you're not hovering on the row
* Non-intrusive as possible in terms of rendering procedure when updateCollection isn't defined (it falls back to regular `getField`)
* Still only works with strings, `null` values update-able as strings
* Delete confirmation using i18n (no translations though)

I might add an 'add document' button in the future, but it gets a little presumptuous. Similar problem with datatypes, but planned to be added in the future also (such as number, boolean and date).

Again, any suggestions for improvements appreciated.