* Overhaul versioncheck system
- Removed version_exeinfo_match, skip_versioncheck, and version_exeinfo_maxdiff from bnetd.conf
- Modified configuration file to use JSON
- Correctly finds the appropriate versioncheck entries
- Add versioncheck.md to docs/
* Update JSON for Modern C++ from 3.0.1 to 3.1.2
* fix randomize banners
* fix miss handling of first banner https://github.com/pvpgn/pvpgn-server/issues/300
* change banners iteration from random to sequence if client support it (actually only warcraft 3 does not support it)
* fix ad000001.smk to show in diablo 2
* return ad000002.smk from old pvpgn for a change