move 3.8 information from HISTORY no NEWS and describe the family changes briefly

HISTORY.txt

-
-What's new in ZODB3 3.8.0?
-==========================
-Release date: ???
-
-- Added support for Blobs. 
-
-BTrees
-------
-
-- Added support for 64-bit integer BTrees as separate types.  
-
-  (For now, we're retaining compile-time support for making the
-   regular integer BTrees 64-bit.)
-
-- Normalize names in modules so that BTrees, Buckets, Sets, and TreeSets can
-  all be accessed with those names in the modules (e.g.,
-  BTrees.IOBTree.BTree).  This is in addition to the older names (e.g.,
-  BTrees.IOBTree.IOBTree).  This allows easier drop-in replacement, which can
-  especially be simplify code for packages that want to support both 32-bit and
-  64-bit BTrees.
-
-- Describe the interfaces for each module and actually declare the interfaces
-  for each.
-
-- Fix module references so klass.__module__ points to the Python wrapper
-  module, not the C extension.
-
-
 What's new in ZODB3 3.7.0?
 ==========================
 Release date: ???

NEWS.txt

@@ -49,6 +49,29 @@ Blobs
   ZODB now handles (reasonably) large binary objects efficiently. Useful to
   use from a few kilobytes to at least multiple hundred megabytes.
 
+BTrees
+------
+
+- Added support for 64-bit integer BTrees as separate types.  
+
+  (For now, we're retaining compile-time support for making the
+   regular integer BTrees 64-bit.)
+
+- Normalize names in modules so that BTrees, Buckets, Sets, and TreeSets can
+  all be accessed with those names in the modules (e.g.,
+  BTrees.IOBTree.BTree).  This is in addition to the older names (e.g.,
+  BTrees.IOBTree.IOBTree).  This allows easier drop-in replacement, which can
+  especially be simplify code for packages that want to support both 32-bit and
+  64-bit BTrees.
+
+- Describe the interfaces for each module and actually declare the interfaces
+  for each.
+
+- Fix module references so klass.__module__ points to the Python wrapper
+  module, not the C extension.
+
+- introduce module families, to group all 32-bit and all 64-bit modules.
+
 
 What's new on ZODB 3.7.0b4?
 ===========================