Add service_context management into libselinux.

Add functions to handle opening handles for MAC
on service_manager. Also add selinux_log_callback
into libselinux because identical code was spread
through three different files.

Bug: 12909011
Change-Id: I04eb855700f1d0c086542053d987b3a30cf1b0c0
diff --git a/Android.mk b/Android.mk
index baec088..7abb19c 100644
--- a/Android.mk
+++ b/Android.mk
@@ -72,4 +72,5 @@
 LOCAL_COPY_HEADERS := $(common_COPY_HEADERS)
 LOCAL_PRELINK_MODULE := false
 LOCAL_STATIC_LIBRARIES := libmincrypt
+LOCAL_SHARED_LIBRARIES := liblog
 include $(BUILD_SHARED_LIBRARY)