Modernize EventPacker
- prefer implicitly generated destructors over explicit trivial destructors
- do not explicitly disable constructors which are not implicitly generated
- remove SVN/CVS keywords
- prefer auto
- prefer SmartIF over raw pointers to services
- avoid copying strins more than strictly neccessary
- prefer emplace_back with no arguments over emplace_back of a default constructed temporary (which will first create and then move-construct the temporary instead of default constructing in-situ)