Bug 151361 default value for reousrce folder user preference
When user does not sepecify the resourec foler user preference, can we make the current project folder (in IDE) or the current report design file's folder (in RCP) as the default value for the resource folder. This way, by default the current project folder is the resource folder where user can create their libs and images. Also please set the default user preference to be null when BIRT is freshly installed.
UI/org.eclipse.birt.report.designer.ui/src/org/eclipse/birt/report/designer/internal/ui/util/UIUtil.java
layout.marginHeight = layout.marginWidth = 0;
		return layout;
	}
	/**
	 * Convert the give string to GUI style, which cannot be null
	 * 
	 * @param string
	 *            the string to convert
	 * @return the string, or an empty string for null
	 */
	public static String convertToGUIString( String string )
	{
		if ( string == null )
		{
			string = ""; 
		}
		return string;
	}
	/**
	 * Convert the give string to Model style
	 * 
	 * @param string
	 *            the string to convert
	 * @param trim
	 *            specify if the string needs to be trimmed
	 * @return the string, or null for an empty string
	 */
	public static String convertToModelString( String string, boolean trim )
	{
		if ( string == null )