Custom pressed states, fixed column sizes.

Use custom pressed state assets.  Use fixed column sizes to prevent
truncating of long dates on small screens.

Also tear down any active CAB when switching fragments.

Bug: 11032418, 11028212
Change-Id: I2bf3dc3f693319b4b55cc901ed460f60faceba35
diff --git a/src/com/android/documentsui/DirectoryFragment.java b/src/com/android/documentsui/DirectoryFragment.java
index 59caad0..4d410d5 100644
--- a/src/com/android/documentsui/DirectoryFragment.java
+++ b/src/com/android/documentsui/DirectoryFragment.java
@@ -216,6 +216,10 @@
             final View view = target.getChildAt(i);
             mRecycleListener.onMovedToScrapHeap(view);
         }
+
+        // Tear down any selection in progress
+        mListView.setChoiceMode(AbsListView.CHOICE_MODE_NONE);
+        mGridView.setChoiceMode(AbsListView.CHOICE_MODE_NONE);
     }
 
     @Override