[Jenne, Sheila]

I have added some logic to the INJECT_SQUEEZING state of ISC_LOCK to reset and then retry squeezing, if the squeezer guardian is stuck.  This is very similar to the reset and retry of the OMC locking that I put in October of 2018 (alog 44481) so that we didn't sit unneccessarily at PREP DC Readout Transition.

This lock acquisition the squeezer was stuck again, thinking that it was locked, but it was not.  Sheila noted that this is a third pathology with the squeezer that we've seen in recent days, although the fix has been basically the same every time: turn it off and turn it on again. (Actually, Sheila has been doing the steps in guardian by hand, but I suspect that it'll be fine if we let guardian retry on its own).

This code has been added to the ISC_LOCK guardian, but not yet loaded.  Operators, if ISC_LOCK is stuck at INJECT_SQUEEZING, please try re-loading the ISC_LOCK guardian.  The guardian will likely be upset (since it'll already be in the Run state, but the timer variable is initialized in the Main state), but you should be able to take ISC_LOCK to Manual, click INJECT_SQUEEZING, then take ISC_LOCK back to Auto, which will force the guardian to restart the state from the beginning and initialize that variable.  If that doesn't work, you can take ISC_LOCK to Manual, click INIT, load the guardian, click INJECT_SQUEEZING, then take ISC_LOCK back to Auto, and that should really force it.

If, after loading the guardian, this has caused any problems, please comment out the following lines, save, then reload the guardian (to take out my changes).  Comment out line 4846 and lines 4860-4864.