Added #defines for using optical flow vs. VRPN and using integrated gyro for yaw. Updated Gyro Z bias. Changed some sensor processing regarding optical flow.
resolves #4
Properly setting sampling time for altitude PID with LiDAR. Fixed HW impl tests for lidar_t changes.
This reverts commit 4f5322d0
Added safety checks for callback function pointer. Updated UART test scripts. Added graph_blocks to XSDK project.