Bug 176681 Issue about creating context-parameter path in read-only path[0601]
Description: Issue about creating context-parameter path in read-only path Build number:2.2.0.v20070308 Steps to reproduce: 1. Deploy birt. 2. Set BIRT_VIEWER_DOCUMENT_FOLDER/BIRT_VIEWER_IMAGE_DIR/.. to a read-only path. 3. Preview report. Expected result: Because the path is read-only, folders should be created in ${java.io.tmpdir} Actual result: No folders are created in ${java.io.tmpdir} and reports cannot be previewed in frameset mode.
viewer/org.eclipse.birt.report.viewer/birt/WEB-INF/classes/org/eclipse/birt/report/utility/ParameterAccessor.java
* 
	 * @param context
	 * @param props
	 * @return
	 */
	public synchronized static Map initViewerProps( ServletContext context,
			Map props )
	{
		
		if ( props == null )
			props = new HashMap( );
		
		String file = context.getInitParameter( INIT_PARAM_CONFIG_FILE );
		if ( file == null || file.trim( ).length( ) <= 0 )
			file = IBirtConstants.DEFAULT_VIEWER_CONFIG_FILE;
		try
		{
			InputStream is = null;
			if ( isRelativePath( file ) )
			{
				
				if ( !file.startsWith( "/" ) ) 
					file = "/" + file; 
				is = context.getResourceAsStream( file );
			}
			else
			{
				
				is = new FileInputStream( file );
			}