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
* Preview report max rows
	 */
	public static int maxRows;
	/**
	 * Current web application locale.
	 */
	public static Locale webAppLocale = null;
	/**
	 * Indicating that if user can only access the files in working folder.
	 */
	public static boolean isWorkingFolderAccessOnly = false;
	/**
	 * Resource path set in the web application.
	 */
	public static String birtResourceFolder = null;
	/**
	 * Flag indicating that if initialize the context.
	 */
	protected static boolean isInitContext = false;
	/**
	 * Overwrite flag
	 */
	public static boolean isOverWrite;
	/**
	 * Application Context Attribute Name
	 */
	public static final String ATTR_APPCONTEXT_KEY = "AppContextKey"; 
	/**
	 * Application Context Attribute value
	 */