New BTree implementation without counts

src/BTrees/IBTree.c

+#define NOVAL
+#define INTKEY int
+#include "BTreeTemplate.c"

src/BTrees/IIBTree.c

+#define INTVAL int
+#define INTKEY int
+#include "BTreeTemplate.c"

src/BTrees/IOBTree.c

+#define INTKEY int
+#include "BTreeTemplate.c"

src/BTrees/OBTree.c

+#define NOVAL
+#include "BTreeTemplate.c"

src/BTrees/OIBTree.c

+#define INTVAL int
+#include "BTreeTemplate.c"

src/BTrees/OOBTree.c

+#include "BTreeTemplate.c"

src/BTrees/Setup

+*shared*
+
+OOBTree OOBTree.c  -I../../Components/ExtensionClass -I../ZODB
+OIBTree OOBTree.c  -I../../Components/ExtensionClass -I../ZODB
+OBTree  OBTree.c   -I../../Components/ExtensionClass -I../ZODB
+IIBTree IIBTree.c  -I../../Components/ExtensionClass -I../ZODB
+IOBTree IOBTree.c  -I../../Components/ExtensionClass -I../ZODB
+IBTree  IBTree.c   -I../../Components/ExtensionClass -I../ZODB

src/BTrees/__init__.py

+import ZODB