Following the mechanical lock-up of the PR3 mirror (3780), I implemented high band width control loops using the oplev signals.

These are different from what Masayuki implemented a month ago (3602) essentially because the mechanical plant changed since then. This time it only uses the IM stage and achieves bandwidth of about 3 Hz for both pitch and yaw. These loops will provide more stable pointing of the interferometer beam to the end stations. Some plots and detailed settings will be posted later.