Try to fix the number of cross-sections
Try to fix the number of cross-sections.
The new default behaviour of the ReaderAsciiHePMC2
is to fill-up the cross-sections to match the number of events.
Some options to keep only one cross-section are provided.
A possible solution for #55.
This MR will require further discussions and follow-ups in #55.
Edited by Andrii Verbytskyi