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 s
	 * @return String
	 */
	public static final String htmlEncode( String s )
	{
		String sHtmlEncoded = ""; 
		if ( s == null )
		{
			return null;
		}
		StringBuffer sbHtmlEncoded = new StringBuffer( );
		final char chrarry[] = s.toCharArray( );
		for ( int i = 0; i < chrarry.length; i++ )
		{
			char c = chrarry[i];
			switch ( c )
			{
				case '\t' :
					sbHtmlEncoded.append( "&#09;" ); 
					break;
				case '\n' :
					sbHtmlEncoded.append( "<br>" ); 
					break;
				case '\r' :
					sbHtmlEncoded.append( "&#13;" ); 
					break;
				case ' ' :
					sbHtmlEncoded.append( "&#32;" ); 
					break;
				case '"' :