Allow the namespace column to be null, and also non-unique. Fix the uncompressed size clobbering the size on the wire field. Add metadata constraints so that foreign key constraints get predictable names. Fix all downgrade migrations.

util/gzipstream.py

@@ -9,17 +9,20 @@ import zlib
 # http://stackoverflow.com/questions/3122145/zlib-error-error-3-while-decompressing-incorrect-header-check/22310760#22310760
 ZLIB_GZIP_WINDOW = zlib.MAX_WBITS | 32
 
+class SizeInfo(object):
+  def __init__(self):
+    self.size = 0
+
 def calculate_size_handler():
   """ Returns an object and a SocketReader handler. The handler will gunzip the data it receives,
       adding the size found to the object.
   """
-  uncompressed_size_info = {
-    'size': 0
-  }
- 
+
+  size_info = SizeInfo()
+
   decompressor = zlib.decompressobj(ZLIB_GZIP_WINDOW)
 
   def fn(buf):
-    uncompressed_size_info['size'] += len(decompressor.decompress(buf))
+    size_info.size += len(decompressor.decompress(buf))
 
-  return uncompressed_size_info, fn
+  return size_info, fn