eFEX offline simulation fixes

A collection of fixes to simulation based on comparisons between recorded real output and emulated (re-simulated) output.

• supercell masking using LAr provenance bits
• eta dependent menu fix
• the overflow is taken care off in expansion
• tau sum is over layer 2 only
• implement max threshold counts for Taus
• the hardware counts down rather than up
• no longer overwrite the tau working points
• deal with wstot max value
• fix rounding of float values, to allow for negative values ... should all be ints