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
* Context parameter name that gives the repository location of the logging
	 * files.
	 */
	public static final String INIT_PARAM_LOG_DIR = "BIRT_VIEWER_LOG_DIR"; 
	/**
	 * Context parameter name that gives the logging level.
	 */
	public static final String INIT_PARAM_LOG_LEVEL = "BIRT_VIEWER_LOG_LEVEL"; 
	/**
	 * Context parameter name that gives the repository location of the script
	 * files to run reports.
	 */
	public static final String INIT_PARAM_SCRIPTLIB_DIR = "BIRT_VIEWER_SCRIPTLIB_DIR"; 
	/**
	 * Context parameter name that determines the search strategy of searching
	 * report resources. True if only search the working folder, otherwise
	 * false.
	 */
	public static final String INIT_PARAM_WORKING_FOLDER_ACCESS_ONLY = "WORKING_FOLDER_ACCESS_ONLY"; 
	/**
	 * The parameter name that gives the repository lication to put the created
	 * documents and report design files.
	 */
	public static final String INIT_PARAM_DOCUMENT_FOLDER = "BIRT_VIEWER_DOCUMENT_FOLDER"; 
	/**
	 * Context parameter name that gives the absolute resource location
	 * directory.
	 */
	public static final String INIT_PARAM_BIRT_RESOURCE_PATH = "BIRT_RESOURCE_PATH"; 
	/**