PY3 make it possible to run some tests in Python3

* switch to Twisted 14.0.0 because SVN version broke twisted.log in Python 3;
* skip top-level shortcuts to make at least some tests pass;
* use PY3 compatible import of _monkeypatches.

scrapy/__init__.py

@@ -17,15 +17,14 @@
 if sys.version_info < (2, 7):
     print("Scrapy %s requires Python 2.7" % __version__)
     sys.exit(1)
-del sys
 
 # Ignore noisy twisted deprecation warnings
 import warnings
 warnings.filterwarnings('ignore', category=DeprecationWarning, module='twisted')
 del warnings
 
 # Apply monkey patches to fix issues in external libraries
-import _monkeypatches
+from . import _monkeypatches
 del _monkeypatches
 
 # WARNING: optional_features set is deprecated and will be removed soon. Do not use.
@@ -53,7 +52,13 @@
     optional_features.add('http11')
 
 # Declare top-level shortcuts
-from scrapy.spider import Spider
-from scrapy.http import Request, FormRequest
-from scrapy.selector import Selector
-from scrapy.item import Item, Field
+if sys.version_info[0] == 2:
+    # Top-level shortcuts are not ready for Python 3 (like most of Scrapy);
+    # skip them here to make at least some parts of Scrapy
+    # importable in Python 3.
+    from scrapy.spider import Spider
+    from scrapy.http import Request, FormRequest
+    from scrapy.selector import Selector
+    from scrapy.item import Item, Field
+
+del sys

tox.ini

@@ -42,7 +42,8 @@ commands =
 [testenv:py33]
 basepython = python3.3
 deps =
-    svn+svn://svn.twistedmatrix.com/svn/Twisted/trunk#egg=Twisted
+;    svn+svn://svn.twistedmatrix.com/svn/Twisted/trunk#egg=Twisted
+    twisted >= 14.0.0
     lxml>=3.2.4
     pyOpenSSL>=0.13.1
     cssselect>=0.9