BaseTools: Use absolute import in AutoGen

Based on "futurize -f libfuturize.fixes.fix_absolute_import

Contributed-under: TianoCore Contribution Agreement 1.1
Cc: Yonghong Zhu <yonghong.zhu@intel.com>
Cc: Liming Gao <liming.gao@intel.com>
Signed-off-by: Gary Lin <glin@suse.com>
Reviewed-by: Jaben Carsey <jaben.carsey@intel.com>

BaseTools/Source/Python/AutoGen/IdfClassObject.py

@@ -13,6 +13,7 @@
 ##
 # Import Modules
 #
+from __future__ import absolute_import
 import Common.EdkLogger as EdkLogger
 from Common.BuildToolError import *
 from Common.StringUtils import GetLineNo
@@ -21,7 +22,7 @@ from Common.LongFilePathSupport import LongFilePath
 import re
 import os
 from Common.GlobalData import gIdentifierPattern
-from UniClassObject import StripComments
+from .UniClassObject import StripComments
 
 IMAGE_TOKEN = re.compile('IMAGE_TOKEN *\(([A-Z0-9_]+) *\)', re.MULTILINE | re.UNICODE)