Port to Python 3.

src/allmydata/__init__.py

@@ -3,6 +3,16 @@ Decentralized storage grid.
 
 community web site: U{https://tahoe-lafs.org/}
 """
+from __future__ import absolute_import
+from __future__ import division
+from __future__ import print_function
+from __future__ import unicode_literals
+
+from future.utils import PY2
+if PY2:
+    # Don't import future str() so we don't break Foolscap serialization on Python 2.
+    from future.builtins import filter, map, zip, ascii, chr, hex, input, next, oct, open, pow, round, super, bytes, dict, list, object, range, max, min  # noqa: F401
+    from past.builtins import unicode as str
 
 __all__ = [
     "__version__",

src/allmydata/test/__init__.py

@@ -132,4 +132,4 @@ if sys.platform == "win32":
 
 from eliot import to_file
 from allmydata.util.jsonbytes import BytesJSONEncoder
-to_file(open("eliot.log", "w"), encoder=BytesJSONEncoder)
+to_file(open("eliot.log", "wb"), encoder=BytesJSONEncoder)

src/allmydata/util/_python3.py

@@ -24,6 +24,7 @@ if PY2:
 
 # Keep these sorted alphabetically, to reduce merge conflicts:
 PORTED_MODULES = [
+    "allmydata",
     "allmydata.__main__",
     "allmydata._auto_deps",
     "allmydata._monkeypatch",