Sliding drawer for roots, move sorting, search.

Move backend root exploration into sliding drawer, and adjust action
bar when moving between modes.  Moves sorting into action bar spinner
instead of separate dialog.  Also add initial search support.

Change-Id: I70189911ba56ae6bd93d5c503a8600acd6d6c0c5
diff --git a/Android.mk b/Android.mk
index 1e45807..853353d 100644
--- a/Android.mk
+++ b/Android.mk
@@ -5,6 +5,8 @@
 
 LOCAL_SRC_FILES := $(call all-subdir-java-files)
 
+LOCAL_STATIC_JAVA_LIBRARIES := android-support-v4
+
 LOCAL_PACKAGE_NAME := DocumentsUI
 LOCAL_CERTIFICATE := platform