Rename old mentionings of APG-named things

Mostly in comments, most importantly: STORE_PATH now ends in
/KeychainBlobs instead of /ApgBlobs

OpenPGP-Keychain/src/main/java/org/sufficientlysecure/keychain/service/KeychainIntentService.java

@@ -855,7 +855,7 @@ public class KeychainIntentService extends IntentService
         if (this.mIsCanceled) {
             return;
         }
-        Log.e(Constants.TAG, "ApgService Exception: ", e);
+        Log.e(Constants.TAG, "KeychainIntentService Exception: ", e);
         e.printStackTrace();
 
         Bundle data = new Bundle();