consistently use Py_TYPE, Py_REFCNT, and correct initializer macros (#3563)

This no-op change makes 2.7 more consistent with 3.x to ease comparison and backports.
diff --git a/Objects/exceptions.c b/Objects/exceptions.c
index 1929777..224d1ba 100644
--- a/Objects/exceptions.c
+++ b/Objects/exceptions.c
@@ -368,8 +368,7 @@
 
 
 static PyTypeObject _PyExc_BaseException = {
-    PyObject_HEAD_INIT(NULL)
-    0,                          /*ob_size*/
+    PyVarObject_HEAD_INIT(NULL, 0)
     EXC_MODULE_NAME "BaseException", /*tp_name*/
     sizeof(PyBaseExceptionObject), /*tp_basicsize*/
     0,                          /*tp_itemsize*/
@@ -419,8 +418,7 @@
  */
 #define SimpleExtendsException(EXCBASE, EXCNAME, EXCDOC) \
 static PyTypeObject _PyExc_ ## EXCNAME = { \
-    PyObject_HEAD_INIT(NULL) \
-    0, \
+    PyVarObject_HEAD_INIT(NULL, 0) \
     EXC_MODULE_NAME # EXCNAME, \
     sizeof(PyBaseExceptionObject), \
     0, (destructor)BaseException_dealloc, 0, 0, 0, 0, 0, 0, 0, \
@@ -435,8 +433,7 @@
 
 #define MiddlingExtendsException(EXCBASE, EXCNAME, EXCSTORE, EXCDOC) \
 static PyTypeObject _PyExc_ ## EXCNAME = { \
-    PyObject_HEAD_INIT(NULL) \
-    0, \
+    PyVarObject_HEAD_INIT(NULL, 0) \
     EXC_MODULE_NAME # EXCNAME, \
     sizeof(Py ## EXCSTORE ## Object), \
     0, (destructor)EXCSTORE ## _dealloc, 0, 0, 0, 0, 0, 0, 0, 0, 0, \
@@ -451,8 +448,7 @@
 
 #define ComplexExtendsException(EXCBASE, EXCNAME, EXCSTORE, EXCDEALLOC, EXCMETHODS, EXCMEMBERS, EXCSTR, EXCDOC) \
 static PyTypeObject _PyExc_ ## EXCNAME = { \
-    PyObject_HEAD_INIT(NULL) \
-    0, \
+    PyVarObject_HEAD_INIT(NULL, 0) \
     EXC_MODULE_NAME # EXCNAME, \
     sizeof(Py ## EXCSTORE ## Object), 0, \
     (destructor)EXCSTORE ## _dealloc, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, \
@@ -1679,8 +1675,7 @@
 }
 
 static PyTypeObject _PyExc_UnicodeEncodeError = {
-    PyObject_HEAD_INIT(NULL)
-    0,
+    PyVarObject_HEAD_INIT(NULL, 0)
     EXC_MODULE_NAME "UnicodeEncodeError",
     sizeof(PyUnicodeErrorObject), 0,
     (destructor)UnicodeError_dealloc, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
@@ -1764,8 +1759,7 @@
 }
 
 static PyTypeObject _PyExc_UnicodeDecodeError = {
-    PyObject_HEAD_INIT(NULL)
-    0,
+    PyVarObject_HEAD_INIT(NULL, 0)
     EXC_MODULE_NAME "UnicodeDecodeError",
     sizeof(PyUnicodeErrorObject), 0,
     (destructor)UnicodeError_dealloc, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
@@ -1862,8 +1856,7 @@
 }
 
 static PyTypeObject _PyExc_UnicodeTranslateError = {
-    PyObject_HEAD_INIT(NULL)
-    0,
+    PyVarObject_HEAD_INIT(NULL, 0)
     EXC_MODULE_NAME "UnicodeTranslateError",
     sizeof(PyUnicodeErrorObject), 0,
     (destructor)UnicodeError_dealloc, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,