Updating Windows Store quickstart to 8.1
Updating Windows Store WinJS quickstart to 8.1
Windows Phone quickstart updates for VS 2013
Updating Windows quickstarts to use Express SKU
Revert "Windows Phone quickstart updates for VS 2013"... for now we want to keep using VS 2012 Express SKU for phone projects.

This reverts commit 567ad3f700a89e0dbda190917389587c102afbb3.
Merge pull request #166 from yavorg/dev

Updating quickstarts for VS 2013 / Windows 8.1