Comply to design guidelines

[ChrisK91]

Microsoft has some basic design guidelines, that are available here:

http://msdn.microsoft.com/en-US/library/windowsphone/design/hh202892(v=vs.105).aspx

We should try to keep our app in concordance with those guidelines. For instance, headers on pivot and panorama items should be lowercase. Also, the Application bar should be minimized on a panorama page as well.