Merge r121631 from /ZODB/branches/jim-python-btrees.

Note that tests don't pass due to a syntax error in the patch:  will
be fixed in merge of the next revision.

BTrees/OOBTree.py

@@ -16,6 +16,31 @@ import zope.interface
 import BTrees.Interfaces
 
 # hack to overcome dynamic-linking headache.
-from _OOBTree import *
+try:
+    from _OOBTree import *
+except ImportError:
+
+    import ___BTree
+
+    class _Base:
+        pass
+
+    class OOBucket(___BTree.Bucket, _Base):
+        MAX_SIZE = 30
+
+    _Base._mapping_type = OOBucket
+
+    class OOSet(___BTree.Set, _Base)):
+        MAX_SIZE = 30
+
+    _Base._set_type = OOSet
+
+    class OOBTree(___BTree.BTree, _Base)):
+        _bucket_type = OOBucket
+        MAX_SIZE = 250
+
+    class OOBTreeSet(___BTree.BTree, _Base)):
+        _bucket_type = OOSet
+        MAX_SIZE = 250
 
 zope.interface.moduleProvides(BTrees.Interfaces.IObjectObjectBTreeModule)