Update Javascript/src/knockout.bindings.dataTables.js

Since Datatables.js 1.9 the property "mDataProp" can be a function (see http://datatables.net/docs/DataTables/1.9.2/DataTable.defaults.columns.html#mDataProp). If a function is registered here, we need to execute it in order to get the values.
dataSource.subscribe checks existance of data not row

Given table binded to an array with 2 items
And table is filtered with XYZ
And none of the 2 items has matching info
When when dataSource updated with new 3 items
And filter XYZ cleared
Then table should clear old data
And show 3 new items

Actual since code checks visible rows and due to filter there are no
visible row, it will not clear table.
To fix it we should check available data.
Updated demo with changes from odugen/knockout.extensions.
Merge branch 'master' of github.com:bertl/Knockout.Extensions

Conflicts:
	Javascript/src/knockout.bindings.dataTables.js