iCloud toggling + internal improvements

[UPDATED]   Change TestFlight preprocessor toggles to
            TESTFLIGHT_SDK_VERSION.
[IMPROVED]  Change logic behind shared MPAppDelegate to inheritance,
            allowing for the common files to implement methods that the
            platform-specific class can override.
[IMPROVED]  Handling and checking of config changes.
[ADDED]     iCloud config toggle, allowing a user to turn on and off
            the iCloud store.
[IMPROVED]  Explanation of iCloud.

MasterPassword/iOS/MPGuideViewController.m

@@ -7,7 +7,8 @@
 //
 
 #import "MPGuideViewController.h"
-#import "MPAppDelegate_Shared.h"
+#import "MPAppDelegate.h"
+
 
 @implementation MPGuideViewController
 @synthesize scrollView;