Improve RS error handling.  On errors RS will now store the error and a message that can be read from the app.  RS will then not continue rendering frames while an unchecked error is present until new state is received.
diff --git a/libs/rs/rsProgram.h b/libs/rs/rsProgram.h
index a34e89f..86f85fb 100644
--- a/libs/rs/rsProgram.h
+++ b/libs/rs/rsProgram.h
@@ -59,6 +59,8 @@
     String8 getGLSLOutputString() const;
     String8 getGLSLConstantString() const;
 
+    bool isValid() const {return mIsValid;}
+
 protected:
     // Components not listed in "in" will be passed though
     // unless overwritten by components in out.
@@ -68,6 +70,7 @@
     uint32_t mInputCount;
     uint32_t mOutputCount;
     uint32_t mConstantCount;
+    bool mIsValid;
 
     ObjectBaseRef<Allocation> mConstants[MAX_UNIFORMS];