v2.8.1

Feature Release with a side of bugfixes!

• Implementation of a grid search-based FIFO analysis called GS. Details:
  Alexander Scheffler, Steffen Bondorf and Jens Schmitt.
  Analyzing FIFO-Multiplexing Tandems with Network Calculus and a Tailored Grid Search (Short Paper).
  In Proc. of the 34th International Teletraffic Congress (ITC), September 2022.
  Dataset
• Instructions on how to use the DNC with the IntelliJ IDE
• Nesting trees will no longer have empty nodes