Simu5G 1.3.0

• Compatible with OMNeT++ 6.1.0 and INET 4.5.4
• New modules: MultiUEMECApp, MecRnisTestApp, UeRnisTestApp
• Added NED documentation for modules
• Increased reusability of modules via changes such as replacing hardcoded module
  paths in the C++ code with NED parameters (binderModule, macModule, etc.), and
  elimination of ancestorPar() calls by introducing local parameters instead.
• Other NED adjustments, such as removal of unused NED parameters and splitting
  NED files to have one module per file. See doc/NED-changes.txt for details.
• Extensive C++ modernization, and adaption of more OMNeT++ best practices.
• Various bug fixes.