Bug 130495 Get rid of SessionHandleAdapter
Now, we use SessionHandleAdapter to keep current active report deisng. That's a bad practive for editor swith and rebuild will cuase lots of problmes. Need find way to replace it.
UI/org.eclipse.birt.report.designer.core/src/org/eclipse/birt/report/designer/core/model/SessionHandleAdapter.java
/**
	 * constructor Mark it to private to avoid new opeartion.
	 */
	private SessionHandleAdapter( )
	{
	}
	public int getFileType( )
	{
		return type;
	}
	private static SessionHandleAdapter sessionAdapter;
	private SessionHandle sessionHandle;
	private ReportDesignHandleAdapter designHandleAdapter;
	/**
	 * Gets singleton instance method
	 * 
	 * @return return SessionHandleAdapter instance
	 */
	public static SessionHandleAdapter getInstance( )
	{
		if ( sessionAdapter == null )
		{
			sessionAdapter = new SessionHandleAdapter( );
		}
		return sessionAdapter;
	}
	/**
	 * @return Session handle
	 */
	public SessionHandle getSessionHandle( )