Xcode 6.1 upgrade
Fix OS X 10.10 warnings

NSApplication was updated in Yosemite to have delegate as a true property, not a getter/setter pair which implicitly behaves as a property. Because of this and because NSApp is of type 'id' not NSApplication*, the only definition of delegate: / setDelegate: methods visible to the compiler is from NSFileManager.
Merge pull request #341 from barijaona/YosemiteSDK

Yosemite SDK
initial skeleton for SubscriptionModel tests
added some simple tests and fixed a bug in Subscription Model's URL verification
added more tests from feedback of issue #315
Merge pull request #343 from josh64x2/subscription-tests

Subscription tests
Fix a crash during refresh

showUnreadCountOnApplicationIconAndWindowTitle must also be runned on the main thread.
Small optimization
GCD version of postNotificationOnMainThreadWithName
Merge pull request #346 from barijaona/bugfixes

Fix a crash, and optimize background refreshes

OK on SL 32bit and Yosemite