Sheila, Camilla, Naoki, remote converations with Vicky

Overnight the squeezing was not injected because of some guardian issues.   The OPO failed to lock, we will look into that separately.

After that the filter cavity did not find IR.  Looking at the logic in SQZ manager, it didn't make sense to me.  We were requesting the filter cavity to IR_FOUND without first locking the OPO or the CLF, but the filter cavity can't find IR until after both the IR and the CLF are locked.  This might have been done to save some time, but it sets up a race condition where we are relying on the filter cavity green locking to be slower than the OPO and CLF locking.  If the filter cavity failed in it's search, then it would stay in FIND_IR and not try again.   I separated the lock OPO and lock cilter cavity states, and rearranged the graph so that the filter cavity isn't requested to lock until after the CLF is requested to lock.  This will take slightly longer but not much longer, and this happens in parallel with IFO locking. We loaded this change and excerised it.

While I was looking at SQZ_MANAGER, I noticed some things that seem potentially confusing and could cause some difficulties with using it.  Several of these related to using the same states for frequency dependent and frequency independent squeezing.  The SQZ manager was looking at the state of the FC guardian to determine if FIS or FDS is desired, in many places.  I changed this so that FIS has a separate path from FDS after the CLF is locked.  This allows simplifying states like OPEN_BDIV (we now have two versions, one for FDS one for FIS).  Some states like LOCK_LO and SQZ_ASC are the same in the two paths, so I've used a generator to make sure that the same code is used in both paths.  Naoki and I checked this, going from DOWN to FDS, FDS to FIS, DOWN TO FIS, and FDS and FIS to no squeezing.  The previous version of the guardian had a path from FDS to FIS, but there was not code to do that so we've now eliminated the path. We made the changes needed to ISC_LOCK, and laoded them.

The guardian before these changes is 27284

The FC_LOCKED checker only checks that the FC gaurdian isn't in IDLE, but it seems to be used througout SQZ_MANAGER as though it was checking the filter cavity is locked.