Add support for launcher shortcuts.

- This CL has no UI but provides the necessary backing for one.
- Adds new item type: ITEM_TYPE_DEEP_SHORTCUT, to distinguish from
  ITEM_TYPE_SHORTCUT. We can reconsider these names.
- Adds ShortcutCache, using LruCache for up to 30 dynamic shortcuts
  (pinned shortcuts are always cached in a HashMap).
- DeepShortcutManager queries for shortcuts and other things like
  pin them. In a future CL it will use the cache, but for now it
  simply makes an RPC for all queries.
- LauncherModel maintains counts for pinned shortcuts, pinning and
  unpinning when counts reach 1 or 0, respectively.
- LauncherModel maintains a map of components to lists of shortcut ids,
  which Launcher gets a copy of after it is changed in the background.
  This will allow us to know how many shortcuts an app has immediately,
  and query for details as the UI is animating.

Change-Id: Ic526f374dd10d72a261bae67f07f098fca8d8bca
diff --git a/src/com/android/launcher3/ItemInfo.java b/src/com/android/launcher3/ItemInfo.java
index 286a7f1..f54a2d4 100644
--- a/src/com/android/launcher3/ItemInfo.java
+++ b/src/com/android/launcher3/ItemInfo.java
@@ -32,7 +32,7 @@
     /**
      * Intent extra to store the profile. Format: UserHandle
      */
-    static final String EXTRA_PROFILE = "profile";
+    public static final String EXTRA_PROFILE = "profile";
 
     public static final int NO_ID = -1;