Added "player destroying" and "player destroyed" hooks

Hooks:
HOOK_PLAYER_DESTROYING
HOOK_PLAYER_DESTROYED

Idea from: https://github.com/mc-server/MCServer/issues/473

src/Entities/Player.cpp

@@ -120,6 +120,8 @@ cPlayer::cPlayer(cClientHandle* a_Client, const AString & a_PlayerName)
 
 cPlayer::~cPlayer(void)
 {
+	cRoot::Get()->GetPluginManager()->CallHookPlayerDestroying(*this);
+
 	LOGD("Deleting cPlayer \"%s\" at %p, ID %d", m_PlayerName.c_str(), this, GetUniqueID());
 	
 	// Notify the server that the player is being destroyed
@@ -134,6 +136,8 @@ cPlayer::~cPlayer(void)
 	delete m_InventoryWindow;
 	
 	LOGD("Player %p deleted", this);
+
+	cRoot::Get()->GetPluginManager()->CallHookPlayerDestroyed(*this);
 }