Bug 178164 Use IEngineTask.status constants and remove unnecessary status variables in EngineTask.
1)Remove following redundant variables in EngineTask used for status info. protected final int RUNNING_STATUS_START = 0; protected final int RUNNING_STATUS_RUNNING = 1; protected final int RUNNING_STATUS_STOP = 2; EngineTask already has access to constants declared in IEngineTask. Use those instead. 2)Remove the unused errorHandlingOption in EngineTask.
engine/org.eclipse.birt.report.engine/src/org/eclipse/birt/report/engine/api/impl/RenderTask.java
{
				throw new EngineException(
						"Render options have to be specified to render a report." ); 
			}
			if ( runnable == null )
			{
				throw new EngineException(
						"Can not find the report design in the report document {0}.",
						new Object[]{reportDoc.getName( )} );
			}
			innerRender.render( );
		}
		finally
		{
			runningStatus = RUNNING_STATUS_STOP;
		}
	}
	/* (non-Javadoc)
	 * @see org.eclipse.birt.report.engine.api.IRenderTask#render()
	 */
	public void setPageNumber( long pageNumber ) throws EngineException
	{
		long totalPage = reportDoc.getPageCount( );
		if ( pageNumber <= 0 || pageNumber > totalPage )
		{
			throw new EngineException( "Page {0} is not found ", new Long( 
					pageNumber ) );
		}
		innerRender = new PageRender( pageNumber);
	}