Emergency fix for py3 breakage introduced in 576f6f (merge of #1538)

Unicode literals (u'foo') aren't valid in Python 3.{1,2} (they will be
again in 3.3, and I failed to notice this.  This is a quick fix, will
discuss further on-list.  But I want master to remain working for py3
users.

IPython/utils/_sysinfo.py

@@ -1,2 +1,2
 # GENERATED BY setup.py
-commit = ''
+commit = ""

setupbase.py

@@ -45,6 +45,9 def oscmd(s):
     print(">", s)
     os.system(s)
 
+# Py3 compatibility hacks, without assuming IPython itself is installed with
+# the full py3compat machinery.
+
 try:
     execfile
 except NameError:
@@ -52,6 +55,11 except NameError:
         locs = locs or globs
         exec(compile(open(fname).read(), fname, "exec"), globs, locs)
 
+try:
+    unicode
+except NameError:
+    unicode = str
+
 # A little utility we'll need below, since glob() does NOT allow you to do
 # exclusion on multiple endings!
 def file_doesnt_endwith(test,endings):
@@ -351,8 +359,8 def record_commit_info(pkg_dir, build_cmd=build_py):
             # We write the installation commit even if it's empty
             out_pth = pjoin(self.build_lib, pkg_dir, 'utils', '_sysinfo.py')
             with io.open(out_pth, 'w') as out_file:
-                out_file.writelines([
-                    u"# GENERATED BY setup.py\n",
-                    u"commit = '%s'\n" % repo_commit,
-                ])
+                out_file.writelines(map(unicode, [
+                    '# GENERATED BY setup.py\n',
+                    'commit = "%s"\n' % repo_commit,
+                ]))
     return MyBuildPy