Bring back Exchange2

Dropped out via r22, but we want this

Change-Id: Iec52790d7c69594d1101d9062fb649a3aca866ab
diff --git a/config/common.mk b/config/common.mk
index 4bdde31..736f1c4 100644
--- a/config/common.mk
+++ b/config/common.mk
@@ -157,6 +157,10 @@
     CMSettingsProvider \
     ExactCalculator
 
+# Exchange support
+PRODUCT_PACKAGES += \
+    Exchange2
+
 # CM Platform Library
 PRODUCT_PACKAGES += \
     org.cyanogenmod.platform-res \