Integration of Limbo Support for Authentication Servers

[bivashy]

Changes:

• [X] Configuration
• [X] End user code (API module)
• [X] Internal code

Detailed change list:

1. Added into LibreLoginPlugin

   @Nullable
   LimboIntegration<S> getLimboIntegration();

2. Added LimboIntegration interface into API module. (https://github.com/kyngs/LibreLogin/commit/248b9f9e26e5f59f5aca6b6e8ce2b08b9ef11171)
3. Added limbo-port-range field into config.conf. (Default value is 30000-40000)
4. Added NanoLimbo support for BungeeCord and Velocity. (Forwarding will be configured automatically)

How to use?

1. Install NanoLimboPlugin
2. Done!

Problems

1. InfoForwardingFactory uses reflection to build InfoForwarding.
2. We cannot initialize NanoLimboIntegration before super.enable() or else we would have such exception (package conflict)

   02:42:25 [WARNING] Exception encountered when loading plugin: LibreLogin
   java.lang.NoClassDefFoundError: xyz/kyngs/librelogin/lib/configurate/serialize/SerializationException
   at xyz.kyngs.librelogin.common.config.ConfigurationKeys.<clinit>(ConfigurationKeys.java:24)
   at xyz.kyngs.librelogin.bungeecord.BungeeCordLibreLogin.enable(BungeeCordLibreLogin.java:87)
   at xyz.kyngs.librelogin.bungeecord.BungeeCordBootstrap.onEnable(BungeeCordBootstrap.java:25)
   at net.md_5.bungee.api.plugin.PluginManager.enablePlugins(PluginManager.java:265)
   at net.md_5.bungee.BungeeCord.start(BungeeCord.java:285)
   at net.md_5.bungee.BungeeCordLauncher.main(BungeeCordLauncher.java:67)
   at net.md_5.bungee.Bootstrap.main(Bootstrap.java:15)
   Caused by: java.lang.ClassNotFoundException: xyz.kyngs.librelogin.lib.configurate.serialize.SerializationException
   at net.md_5.bungee.api.plugin.PluginClassloader.loadClass0(PluginClassloader.java:103)
   at net.md_5.bungee.api.plugin.PluginClassloader.loadClass(PluginClassloader.java:59)
   at java.base/java.lang.ClassLoader.loadClass(ClassLoader.java:520)
   ... 7 more

Problems can be fixed just by modifying NanoLimboPlugin.

[bivashy]

Hello, sorry for delay

I am touching internal classes because otherwise we should've create configuration, that would mean that this 'Integration' should be configured. I thought it is better if everything is pre-configured (info forwarding too). About DummyCommandHandler, it is required in LimboServer constructor

[kyngs]

Okay, the code looks good, I will test this soon:tm: and then I'll merge it

[kyngs]

Just tested it and it looks great, thanks!