Bug 152443 Support boolean type in data set
Support boolean type in data set. It'll cause some data transform issue with absence of boolean type.
core/org.eclipse.birt.core/src/org/eclipse/birt/core/data/DataTypeUtil.java
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 :
				return toDouble( source );
			case DataType.STRING_TYPE :
				return toString( source );
			case DataType.BLOB_TYPE :
				return toBlob( source );
			case DataType.BINARY_TYPE :
				return toBytes( source );
			default :
				throw new CoreException( ResourceConstants.INVALID_TYPE,
						resourceBundle );
		}
	}
	/**
	 * convert a object to given class
	 * Classes supported:
	 * 		Integer.class
	 * 		BigDecimal.class
	 * 		Boolean.class
     *      Time.class