Fix Python 3.2 test failures (ResourceWarnings from unclosed files).

Closes gh-2083.

IPython/utils/py3compat.py

@@ -73,7 +73,8 b' if sys.version_info[0] >= 3:'
     
     def execfile(fname, glob, loc=None):
         loc = loc if (loc is not None) else glob
-        exec compile(open(fname, 'rb').read(), fname, 'exec') in glob, loc
+        with open(fname, 'rb') as f:
+            exec compile(f.read(), fname, 'exec') in glob, loc
     
     # Refactor print statements in doctests.
     _print_statement_re = re.compile(r"\bprint (?P<expr>.*)$", re.MULTILINE)