Resolve "Summary TeX file does not format cutflow diagram properly"

Release notes

Fixed drawing of cutflow diagram in summary TeX file

Details

The __baseCut__ at the trunk of every cutflow is not liked for its underscores in the name.
Including the underscore package from within the cuts.tex on \input{} fixes this, by instructing the standalone package to also include their preambles.
This way, the use of the underscore package doesn't interfere with other underscores used in the summary document, eg. file names.

Closes #311 (closed)