Fix most trivially-findable print statements.

There's one major and one minor category still unfixed:
doctests are the major category (and I hope to be able to augment the
refactoring tool to refactor bona fide doctests soon);
other code generating print statements in strings is the minor category.

(Oh, and I don't know if the compiler package works.)
diff --git a/Lib/popen2.py b/Lib/popen2.py
index 694979e..3618487 100644
--- a/Lib/popen2.py
+++ b/Lib/popen2.py
@@ -213,14 +213,14 @@
     # sometimes adding an extra newline at the start or the
     # end.  So we strip whitespace off both ends for comparison.
     expected = teststr.strip()
-    print "testing popen2..."
+    print("testing popen2...")
     r, w = popen2(cmd)
     w.write(teststr)
     w.close()
     got = r.read()
     if got.strip() != expected:
         raise ValueError("wrote %r read %r" % (teststr, got))
-    print "testing popen3..."
+    print("testing popen3...")
     try:
         r, w, e = popen3([cmd])
     except:
@@ -238,7 +238,7 @@
     _cleanup()
     if _active:
         raise ValueError("_active not empty")
-    print "All OK"
+    print("All OK")
 
 if __name__ == '__main__':
     _test()