Improvement to extended data table auto sort feature

One of the limitations of the initial auto sort feature was that it work by making all columns sortable, couldn't choose which one exactly if needed. I've been working on it, and now this is resolved. Two new attributes on the tomahawk table column, "sortable" and "sortPropertyName" can enable auto sorting only the columns that are needed. I also created a new example page to demonstrate how this works.

I hope you'll find this usefull too.

Regards,
Catalin