Tweak SPDispatchAsync to use a less common block name

Change-Id: I28534cff784f33c0c787657e57c3a09c1ff98bd5
Add SPPartialAsyncLoading protocol

Change-Id: Ib9ec945076d8e015d71f22b651734e99b6c59617
Add SPSparseList

Change-Id: Ife5c6db1c6cab5cc8bc164537e1163eac1af1447
Update Mac Offline Playlists example to use SPSparseList

Change-Id: Iac06c5320b3371ac74d8de4936f30fa4eccb94f7