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/ui/ReportPlugin.java
*            The specified element name
	 * @return String[] The array of strings
	 */
	private String[] convert( String preferenceValue )
	{
		String preferenceValueCopy = new String( );
		preferenceValueCopy = new String( PREFERENCE_DELIMITER )
				+ preferenceValue;
		String replaceString = new String( PREFERENCE_DELIMITER )
				+ new String( PREFERENCE_DELIMITER );
		String regrex = new String( PREFERENCE_DELIMITER )
				+ SPACE
				+ new String( PREFERENCE_DELIMITER );
		while ( preferenceValueCopy.indexOf( replaceString ) != -1 )
		{
			preferenceValueCopy = preferenceValueCopy.replaceFirst( replaceString,
					regrex );
		}
		StringTokenizer tokenizer = new StringTokenizer( preferenceValueCopy,
				PREFERENCE_DELIMITER );
		int tokenCount = tokenizer.countTokens( );
		String[] elements = new String[tokenCount];
		int i;
		for ( i = 0; i < tokenCount; i++ )
		{
			elements[i] = tokenizer.nextToken( ).trim( );
		}
		return elements;
	}
	/**