Transition support library

This new library currently supports some basic features of Transition
API.  Scene, Fade, ChangeBounds, TransitionSet, AutoTransition and
TransitionManager have been back-ported except for XML.

Change-Id: I75e9e4d6d7f366297f69735adec0842784290329
diff --git a/settings.gradle b/settings.gradle
index 0e5c223..13d0996 100644
--- a/settings.gradle
+++ b/settings.gradle
@@ -59,3 +59,6 @@
 include ':support-animated-vector-drawable'
 project(':support-animated-vector-drawable').projectDir = new File(rootDir, 'graphics/drawable/animated')
 
+include ':support-transition'
+project(':support-transition').projectDir = new File(rootDir, 'transition')
+