Cleanup sendToClient and add rsGetDt().
Remove legacy implemtation of matrix calls which were moved to llvm bc.

Change-Id: I527740590067db3bcb2147233ef41fb057f1d2a8
diff --git a/libs/rs/rsScript.h b/libs/rs/rsScript.h
index 0717059..455ece7 100644
--- a/libs/rs/rsScript.h
+++ b/libs/rs/rsScript.h
@@ -40,7 +40,8 @@
     virtual ~Script();
 
     struct Enviroment_t {
-        uint32_t mStartTimeMillis;
+        int64_t mStartTimeMillis;
+        int64_t mLastDtTime;
         const char* mTimeZone;
 
         ObjectBaseRef<ProgramVertex> mVertex;