Move W8/JS test app one level up in preparation to merging  with the HTML/JS test app.

There are now two JS SDKs - one for Windows Store applications, and one for "pure" HTML/JS apps. Currently we only have one test application (for WinStore/JS) under test/W8, so to be able to reuse code between this and the new test app for the HTML/JS SDK, this commit moves the test app outside the W8 folder.