Bug 214204 Only document content in document folder should be removed.[0601]
Description: Only document related content in document folder should be removed. Build number:2.3.0.v20080103 Steps to reproduce: 1. Deploy BIRT. 2. Edit web.xml to set BIRT_VIEWER_DOCUMENT_FOLDER to your local path and there are content inside the path. 3. Start server and click View Example to preview sample report. Expected result: Only content created by viewer should be removed in specified document folder. Actual result: All contents are deleted despite whether they are related with BIRT. Error log:n/a
viewer/org.eclipse.birt.report.viewer/birt/WEB-INF/classes/org/eclipse/birt/report/utility/ParameterAccessor.java
* @return
	 */
	public static Number getDpi( HttpServletRequest request )
	{
		String dpi = getParameter( request, PARAM_DPI );
		if ( dpi == null || dpi.trim( ).length( ) <= 0 )
			return null;
		return Integer.valueOf( dpi );
	}
	/**
	 * Returns the separator String
	 * 
	 * @param request
	 * @return
	 */
	public static char getSep( HttpServletRequest request )
	{
		String sepKey = getParameter( request, PARAM_SEP );
		if ( sepKey == null )
			return DEFAULT_SEP;
		String key = "viewer.sep." + sepKey; 
		String sep = getInitProp( key );
		if ( sep == null || sep.length( ) <= 0 )
			return DEFAULT_SEP;
		return sep.charAt( 0 );
	}
	/**
	 * Returns whether exports column's data type
	 * 
	 * @param request