Safer migration, boolean description fix.

[ADDED]     Safer store migration: don't delete the old store, allowing the client to downgrade.
[ADDED]     Log checkpoints and send to TestFlight too.
[FIXED]     Describe booleans as YES/NO, not 1/0.
Merge branch 'master' of github.com:Lyndir/MasterPassword
Work-around for a weird Core Data bug.
Fix sign comparison of enum.
More compatible way of specifying icon files.

[FIXED]     Add extensions to Icon as well to CFBundleIconFiles because Xcode doesn't seem to listen to the Apple docs.
Info.plist fixes.

[FIXED]     Add extensions to Icon as well to CFBundleIconFiles because Xcode doesn't seem to listen to the Apple docs.
[FIXED]     Removed newsstand metadata: this is not a newsstand app.