Support searching and sorting on rendered field values containing joined data

When I try to search for some particular content in datatable, the search doesn't really work.
To give you an example:

``` js
X = new orion.collection('x', {
...
tabular: {
columns: [
{ data: "id", title: "ID" },
{ data: "creditor", title: "Creditor", render: function (val, type, doc) {
var x = Creditors.findOne(val);
if(!x)
return val + " not found";
return x.name;
}
},
]
}
```

```
TABLE:
ID -> 1010
C --> Tom Jones

SEARCH RESULTS:
"10" -> nothing
"1010" -> returns actual row
"Tom" --> nothing
"Tom Jones" --> nothing
```

So where ever I have render property, search returns nothing but also where I don't have render, search only returns result if input text is complete value, not a substring of table column content. I am subscribed to Creditors so that's not the problem.

Start with the tabular column search and sorting behavior, using the issue's rendered `creditor` column example with joined `Creditors` data. Reproduce searches for partial IDs and rendered names such as "10" and "Tom". Done means searching and sorting work for rendered values and substring matches, including values assembled from joined data.

Written by the indexing model from the issue text.