Bug 213126 Add support for DataEngine-leve dataset cache
In many cases the DataEngine-leve dataset cache is useful which ensure that a dataset is executed one time during rendering one report. To support this feature a new dataset property should be added. The Birt customer can choose whether this dataset need to be cached or not by setting the property in deisgn time.
model/org.eclipse.birt.report.model/src/org/eclipse/birt/report/model/writer/ModuleWriter.java
EmbeddedImage.DATA_MEMBER ) ) != null )
					{
						byte[] data = base
								.encode( image.getData( getModule( ) ) );
						String value = new String( data, EmbeddedImage.CHARSET );
						if ( value.length( ) < IndentableXMLWriter.MAX_CHARS_PER_LINE )
							writeEntry( DesignSchemaConstants.PROPERTY_TAG,
									EmbeddedImage.DATA_MEMBER, null, value,
									false );
						else
							writeLongIndentText(
									DesignSchemaConstants.PROPERTY_TAG,
									EmbeddedImage.DATA_MEMBER, value );
					}
				}
				catch ( UnsupportedEncodingException e )
				{
					assert false;
				}
				writer.endElement( );
			}
			writer.endElement( );
		}
	}
	/**
	 * Visits the translations of the module.
	 * 
	 * @param obj
	 *            the module to traverse
	 */