Add possibility to sort disable a specific item

[iamajoe]

This came from a situation where I wanted to setup header items that I didn't want to move. This could be useful in other situations aswell.

Here is an example usage:

const data = [
  { text: 'Foo', sortDisabled: true },
  { text: 'Bar' }
];

The first data item wouldn't be sort enabled but the second one would.