Update PlayerMap(s) from plshared.
Add UUIDs internally, look up players by UUID for PEX, if available.

This is not full-UUID-compatibility yet, because storage is still by
player names, however the step towards that is not that big anymore.

Note that some API still remains with player names, because they run on
online players. RSP provides an onlin-player map to get players by UUID
or name.
Prepare bigger changes.

Planned are:
* Move WorldGuard dependency into a sub-component.
* Add support for auto-permissions for players (uuid or name or file).
[BREAKING] Reduce dependency on WorldGuard, replace ISetCheck.

Switched to a generic regions implementation internally. ISetCheck is
replaced by IRegionResultHook, adding the UUID of the player and
changing to RegionResult containing only string ids.

Generic factory handling and registration is not yet implemented, so it
is not yet possible to use something else instead of WoirldGuard.
Encapsulate action on player join and leave in RSPCore methods.
Adjust project structure. Prepare auto-add.
Use recheckAllPlayers with reloading settings instead of just check.
 [SAFETY COMMIT] Revert using recheck, prepare auto-add-groups.
Reinstate recheckAll instead of checkAll.
Clear groups on checkout.
First raw sketch of auto-add-groups.