Bug 169675 rptdocument folder should be configurable independent of the rptdesign folder
The folder in which rptdesign Report Design files are stored can be configured using the context parameters BIRT_VIEWER_WORKING_FOLDER or BIRT_VIEWER_DOCUMENT_FOLDER. But: The rptdocument files (generated temporarily during runtime) are always stored in a subfolder of the rptdesign folder called "documents". This behaviour is hard-coded. It should be configurable instead: We should have the possibility to place the rptdesign files in one folder, and the rptdocuments in a completely different folder, not necessarily a subdir of the rptdesign folder. This especially because the rptdocument files are created during run-time. In some production environments no write access is granted to the deployment dirs. In that case it would be necessary to point the rptdocument folder to some temp dir. Ideally, the environment variable "java.io.tmpdir" would be supported for this purpose as well.
viewer/org.eclipse.birt.report.viewer/birt/WEB-INF/classes/org/eclipse/birt/report/utility/ParameterAccessor.java
* Format parameter constants to display the report in html.
	 */
	public static final String PARAM_FORMAT_HTM = "htm"; 
	public static final String PARAM_FORMAT_HTML = "html"; 
	/**
	 * Format parameter constants to display the report in pdf.
	 */
	public static final String PARAM_FORMAT_PDF = "pdf"; 
	/**
	 * URL parameter name that gives the locale.
	 */
	public static final String PARAM_LOCALE = "__locale"; 
	/**
	 * URL parameter name that determins to support the SVG or not.
	 */
	public static final String PARAM_SVG = "__svg"; 
	/**
	 * URL parameter name that gives the page number to display the report.
	 */
	public static final String PARAM_PAGE = "__page"; 
	/**
	 * URL parameter name that gives the page range to display the report.
	 */
	public static final String PARAM_PAGE_RANGE = "__pagerange"; 
	/**
	 * URL parameter name that gives the report design name.
	 */
	public static final String PARAM_ISNULL = "__isnull"; 
	/**
	 * URL parameter name that indicate the report parameter as a locale string.