WIP: Allow for running on PbPb MC
This MR increases the minimum size of slices allocated by the MDFProvider, allowing for running over (at least some) PbPb events. This requires dumping the PbPb MC to MDF files and running in standalone mode, and only the CPU build has been tested. This is a temporary band-aid to get around #281 (closed) and allow for some PbPb trigger development.
FYI @baudurie