Description

In the case that LuckPerms detects a plugin such as PermissionsEx, PowerRanks, etc is installed on the server too, it would alert the server owner to this.

Proposed behaviour

It could output in a few places depending on which would work best:

• It could output into console on boot - although this might be missed by some users
• It could output to console whenever a player joins
• It could output whenever an OP'd player joins the game (can't check permissions for the alert, as obviously permissions will be fucked if multiple plugins are installed)
• It could output at the bottom / top of every /lp command that is ran

The commit above adds a mesage to the console / log file every time a player connects and another permission plugin is detected.

Some permission plugins (those that conform strictly to the Bukkit PermissionAttachment API) actually will be compatible - it's just other plugins that inject using reflection like LP does which won't be. It makes sense to have a generic check there instead of a hardcoded list of other permission plugins to detect IMO.

Thanks for the suggestion! :)