Patches for legacy productions and improved stability (v4r1p1 candidate)

This patch deals with issues reported by @svende and improves stability of the statistics table generation script in case the parsing and/or merging of XML generator logs fails. I introduced a tolerance of order 0.05% when comparing the generated interactions and the sum of interactions reported in cross-section counters (apparently for older software stack these values are not equal though the XML log version is 1.1 or later).