#1031 Introduce hasSession field in datasource (#1351)

* Introduce hasSession field in datasource

That makes isLogged more consistent as it will be '1' only when the player is online.

* Fixes

* Fix unit testing

* Update config doc

* Create SessionService

* Create test for SessionService, avoid DB operations if sessions are disabled

* Cleanup: remove outdated warning for session timeout = 0
- Remove outdated warning
- Encapsulate session enabled check in SessionService

* Fix failing SessionServiceTest, add data source integration tests for session methods

src/test/resources/fr/xephi/authme/datasource/sql-initialize.sql

@@ -13,10 +13,12 @@ CREATE TABLE authme (
     yaw FLOAT,
     pitch FLOAT,
     email VARCHAR(255) DEFAULT 'your@email.com', 
-    isLogged INT DEFAULT '0', realname VARCHAR(255) NOT NULL DEFAULT 'Player', 
+    isLogged INT DEFAULT '0',
+    realname VARCHAR(255) NOT NULL DEFAULT 'Player',
     salt varchar(255),
     recoverycode VARCHAR(20),
     recoveryexpiration BIGINT,
+    hasSession INT NOT NULL DEFAULT '0',
     CONSTRAINT table_const_prim PRIMARY KEY (id)
 );