Pubstwo 873

Refactored links.js. Created a new module pw.dataList which contains a ListOrderingService and a simple directive pwDataRowList which decorates a data row with a delete button and drag handle. We should be able to reuse both of this in the Collaborators tab.

Wrote tests for both links.js and dataList.js
Yay for promises! And for making it actually use the response once the promise is resolved!