[1.5.0] Added a whitelist, country filtering, important fixes and much more

This update fixes a lot of things and adds the very requested whitelisting feature. Country filtering was also added!

• Added a whitelisting system with config, country filter, and much more, as well as some other code improvements (from 1.5.0 Beta 1). Check addons/sourcemod/configs/no_dupe_account.cfg
• Fixed Steam web requests randomly failing from time to time by adding a retry system. More logging has also been added, as well as specific error messages to help users and developers understand the problem. (#12, #29)
  • The web requests are now done a bit differently. We didn't find any bug in our testing, but if you find any, please report it!
• Switched to kidfearless/Auto-Exec-Config-Class (also known as convar_class). This will automatically update each cvar infos when switching versions (updates description & default value, removes old cvars and adds new ones, without changing the values you configured!). You won't have to delete and back up the cvars config file anymore! (#30)
• Updated some Portuguese translations (#27 by @crashzk)
• Changed database handle to its methodmap equivalent (#9)
• Fixed global arrays not initiating with good values (#24)
• Potentially fixed players being kicked for having a Community Ban when they actually didn't have one (potentially caused by Steam Maintenances) (#28)
• Added more logging with nda_log 3 (#26)