BUG: revert 2/3 changes in vbsuite
Fixes #4477,  #4474

Can you take care of #4474 as well please?
 done. I just checked out vb_suite from 338f3406fadc6d114accbc94fac6c7ba075a10f5 - I don't think there were any other changes aside from 2to3 related ones, so probably should be okay. You might want to confirm that (tried to look through the diff). I have to run but can look again tonight.
 @jreback this just popped up on Travis - any idea? Given that this only changes vb_suite, I'm pretty sure it's unrelated.

```
======================================================================
ERROR: test_string_select (pandas.io.tests.test_pytables.TestHDFStore)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/home/travis/virtualenv/python2.7_with_system_site_packages/local/lib/python2.7/site-packages/pandas-0.11.0_1052_g7ad2e48-py2.7-linux-x86_64.egg/pandas/io/tests/test_pytables.py", line 2424, in test_string_select
    result = store.select('df',Term('x!=none'))
  File "/home/travis/virtualenv/python2.7_with_system_site_packages/local/lib/python2.7/site-packages/pandas-0.11.0_1052_g7ad2e48-py2.7-linux-x86_64.egg/pandas/io/pytables.py", line 475, in select
    raise KeyError('No object named %s in the file' % key)
KeyError: 'No object named df in the file'
----------------------------------------------------------------------
```
 sometimes I see a random failure on travis (but can't reproduce it outside)....maybe a writing to disk error of some kind...if it reproduces let me know
 @jreback just happened twice in a row.
 @jreback trying it again, maybe it'll work this time...
 Actually every commit I've pushed based off of master:
- https://travis-ci.org/jtratner/pandas/builds/9896736
- https://travis-ci.org/jtratner/pandas/builds/9896602
- https://travis-ci.org/jtratner/pandas/builds/9896231
- https://travis-ci.org/jtratner/pandas/builds/9896231

etc.
 hmm...that is weird...let me pull down your branch
 works fine for me (both 32/64 bit)
 This commit is just current master failing with the same issue - https://travis-ci.org/jtratner/pandas/builds/9897047
 are you sure you are completely rebased, I did push a fix last night to master (and in between I don't know what it would do)
 current master is fine
 @jreback can you checkout a branch off of master and force Travis to build? I keep getting issues with commits that are _exactly_ the same as master. This time I deleted my master branch, checked out pydata/pandas@master and then push to my own branch - still failed.
 @jtratner fyi...@cpcloud ran into the same problem....but noone can repro (even on a very travis like machine), then suddenly went away....weird
 tell you what...why don't I just merge this branch....?
 @jreback haha, your call. But just be aware that this just failed about 2 minutes ago b/c of the same issue cropping up again :-/
 let's see how master does....problem is I CAN't repoduce, nor could @cpcloud locally at all (even on a box exactl like travis), 32-bit, same exact versions of tables,numexpr,numpy,python....really odd
 ok....failed (same test)...let me see
 ok...its fixed, but I all I did was this (which I am now going to take out)....maybe its some weird whitespace issue????
https://github.com/pydata/pandas/commit/f08fb8984363ca9e88d9e95f0ea85d73fe5b0ae0
 @jtratner master looks good now....very weird error
