Added a bias to alt weights so in-between tags prefer larger tags

This bias makes it so that tag lookups always find a tag strictly >= the
requested tag, unless we are at the end of the tree.

This makes tree traversal trivial, which is quite nice.

Need to remove ntag now, it's no longer needed.

scripts/dbgrbyd.py

@@ -176,6 +176,19 @@ def main(disk, block_size, block1, block2=None, **args):
             '  (%s)' % ', '.join(notes)
                 if notes else ''))
 
+        if args.get('device'):
+            print('%8s  %-47s  %08x %x' % (
+                '',
+                '%-22s%s' % (
+                    '%08x %08x' % (tag, size),
+                    '  %s' % ' '.join(
+                            '%08x' % struct.unpack('<I',
+                                data[j_+delta+i*4:j_+delta+i*4+4])
+                            for i in range(min(size//4, 3)))[:23]
+                        if not tag & 0x4 else ''),
+                crc,
+                popc(crc) & 1))
+
         if args.get('raw'):
             for o, line in enumerate(xxd(data[j_:j_+delta])):
                 print('%8s: %s' % ('%04x' % (j_ + o*16), line))
@@ -213,9 +226,13 @@ if __name__ == "__main__":
         action='store_true',
         help="Don't stop parsing on bad commits.")
     parser.add_argument(
-        '-R', '--raw',
+        '-r', '--raw',
         action='store_true',
         help="Show the raw data including tag encodings.")
+    parser.add_argument(
+        '-x', '--device',
+        action='store_true',
+        help="Show the device-side representation of tags.")
     parser.add_argument(
         '-T', '--no-truncate',
         action='store_true',