erp5: py3: Use future egg API to install module aliases on Python2 for modules moved in Python3.

Also, patch future so that it does not use unicode_literals and str() as
unicode() because this breaks compatibility: all of this API (such as unquote()
from urllib, used in BusinessTemplate) used to return str(), not unicode().

stack/erp5/buildout.cfg

@@ -335,6 +335,7 @@ recipe = slapos.recipe.build:gitclone
 repository = https://lab.nexedi.com/nexedi/erp5.git
 branch = master
 git-executable = ${git:location}/bin/git
+develop = true
 
 [testrunner]
 # XXX: Workaround for fact ERP5Type is not an distribution and does not
@@ -346,6 +347,8 @@ entry-points =
   runUnitTest=runUnitTest:main
 scripts = runUnitTest
 initialization =
+  from future import standard_library
+  standard_library.install_aliases()
   import glob, os, sys
   import Products
   Products.__path__[:0] = filter(None,
@@ -378,6 +381,8 @@ entry-points =
   runTestSuite=Products.ERP5Type.tests.runTestSuite:main
 scripts = runTestSuite
 initialization =
+  from future import standard_library
+  standard_library.install_aliases()
   import os
   import sys
   import Products
@@ -560,6 +565,9 @@ eggs = ${neoppod:eggs}
   strict-rfc3339
   jsonschema[format]
 
+# py3
+  future
+
 # parameterizing the version of the generated python interpreter name by the
 # python section version causes dependency between this egg section and the
 # installation of python, which we don't want on an instance
@@ -590,6 +598,8 @@ python-magic-patches = ${:_profile_base_location_}/../../component/egg-patch/pyt
 python-magic-patch-options = -p1
 Zope2-patches = ${:_profile_base_location_}/../../component/egg-patch/Zope/PythonScript-2.13.patch#124c0d37394dd5020c6fd241ad75cc29
 Zope2-patch-options = -p1
+future-patches = ${:_profile_base_location_}/../../component/egg-patch/future/future-no-unicode-literals.patch#695a92b98c311431033207228208a7b0
+future-patch-options = -p1
 
 [eggs-all-scripts]
 recipe = zc.recipe.egg
@@ -767,10 +777,12 @@ Beaker = 1.11.0
 Mako = 1.1.4
 pyjwkest = 1.4.2
 alabaster = 0.7.12
-future = 0.18.2
 pycryptodomex = 3.10.1
 
 strict-rfc3339 = 0.7
 webcolors = 1.10
 rfc3987 = 1.3.8
 jsonpointer = 2.2
+
+# py3 support
+future = 0.18.2+SlapOSPatched001