Merge branch '2.3.x' into dev

* 2.3.x:
  Comment #289 Hasten garbage collection of Connections after close
  Comment #289 Hasten garbage collection of Connections after close

Conflicts:
	hikaricp-java6/src/main/java/com/zaxxer/hikari/pool/HikariPool.java
	hikaricp/src/main/java/com/zaxxer/hikari/pool/HikariPool.java

src/main/java/com/zaxxer/hikari/pool/PoolBagEntry.java

@@ -31,7 +31,7 @@ public final class PoolBagEntry implements IConcurrentBagEntry
 {
    public final AtomicInteger state = new AtomicInteger();
 
-   public final Connection connection;
+   public Connection connection;
    public long lastOpenTime;
    public volatile boolean evicted;
    public volatile boolean aborted;