Bug 148392 Float type fails to be retrieven in scripted datasets
1/ Create a scripted dataset with Float type values, retrive them in the fetch dataset's method configure the output columns and assign them the Float type => result preview fails to show the float columns values 2/ Set the columns' type as Any => the result preview shows normally 3/ Create a chart based on the previous dataset configure the databindings setting float as the said columns type (the dataset's type is Any) => the series fails to appear in the graph (see error in footer) 4/ Change the data bindings for the said columns as Any and use the series fromatting to fix it => the series appears normally
core/org.eclipse.birt.core/src/org/eclipse/birt/core/data/DataTypeUtil.java
* 		DataType.STRING_TYPE
	 * 		DataType.BLOB_TYPE
	 * @param source
	 * @param toType
	 * @return
	 * @throws BirtException
	 */
	public static Object convert( Object source, int toType )
			throws BirtException
	{
		if ( source == null )
			return null;
		
		
		if ( toType == DataType.UNKNOWN_TYPE || toType == DataType.ANY_TYPE )
			return source;
		
		source = JavascriptEvalUtil.convertJavascriptValue( source );
		
		switch ( toType )
		{
			case DataType.INTEGER_TYPE :
				return toInteger( source );
			case DataType.DECIMAL_TYPE :
				return toBigDecimal( source );
			case DataType.BOOLEAN_TYPE :
				return toBoolean( source );
			case DataType.DATE_TYPE :
				return toDate( source );
			case DataType.DOUBLE_TYPE :