Added safety checks for callback function pointer. Updated UART test scripts....

Added safety checks for callback function pointer. Updated UART test scripts. Added graph_blocks to XSDK project.

quad/xsdk_workspace/modular_quad_pid/Release/src/subdir.mk

@@ -53,7 +53,7 @@ C_DEPS += \
 src/%.o: ../src/%.c
 	@echo 'Building file: $<'
 	@echo 'Invoking: ARM gcc compiler'
-	arm-xilinx-eabi-gcc -DNDEBUG=1 -Wall -O2 -I../../system_bsp/ps7_cortexa9_0/include -I"/local/ucart/MicroCART_17-18/quad/src/computation_graph" -I"/local/ucart/MicroCART_17-18/quad/src/quad_app" -I"/local/ucart/MicroCART_17-18/quad/src/queue" -I"/local/ucart/MicroCART_17-18/quad/src/commands" -c -fmessage-length=0 -MMD -MP -MF"$(@:%.o=%.d)" -MT"$(@:%.o=%.d)" -o "$@" "$<"
+	arm-xilinx-eabi-gcc -DNDEBUG=1 -Wall -O2 -I../../system_bsp/ps7_cortexa9_0/include -I"/local/ucart/MicroCART_17-18/quad/src/computation_graph" -I"/local/ucart/MicroCART_17-18/quad/src/quad_app" -I"/local/ucart/MicroCART_17-18/quad/src/queue" -I"/local/ucart/MicroCART_17-18/quad/src/commands" -I"/local/ucart/MicroCART_17-18/quad/src/graph_blocks" -c -fmessage-length=0 -MMD -MP -MF"$(@:%.o=%.d)" -MT"$(@:%.o=%.d)" -o "$@" "$<"
 	@echo 'Finished building: $<'
 	@echo ' '