Leginon

The error comes from scipy.optimize.leastsq function where it gave the exception when 6 out of the 8 data input arrays (tilt series of limited tilt range in this case) are empty.

r15317 avoids this by popping the empty data and parameters from the input to the function. Tested fine in simulation. Will test on real scope before merge to branches.

r15318 are simulator enhancement in collectionsimu.py used to debug this and some minor bug fix noticed during thie in tomographysimu.py. These will not need to be merged to branches

Real testing:
Do this in Leginon Tomography application
1. Collect at least 6 tilt series that only cover minimal tilt angle range.
2. Collect a tilt series up to much higher tilts so that it has at least 4 higher tilts not found in the earlier tilt series.
3. The old code would give error but the new one won't and could complete the tilt series.

have not seen problem for a long time.