[TIMOB-19127] Windows: Ti.Platform.createUUID() should not have curly brackets

The following code:

var win = Ti.UI.createWindow();
console.error(Ti.Platform.createUUID());
win.open();

Will have the following type of output on: * iOS: *D614A644-4B66-41DB-9874-7A4BC9913FC2* * Android: *08c67469-3b8c-48ec-8fde-499ec520407a* * Windows: *\{5ec8919e-5681-49af-8ee4-da2522a47194\}* The difference in lower and upper case is trivial, but the curly brackets on Windows will break stuff. In fact, the Analytics on Windows is already working around it: https://github.com/appcelerator/titanium_mobile_windows/blob/master/Source/TitaniumKit/src/analytics.js#L32 The type of output should be identical on all platforms.