Very initial commit to support Rails 3.2 by rails4 branch

[Yasuo Honda]

Hi,

I've been working to support Rails 3.2 by rails4 branch. Still got a
lot of failures.

https://github.com/yahonda/oracle-enhanced/commit/15f3db1b39b09b260a28947dec9dd910877101a0#commitcomment-2773501

It's a initial commit to support Rails 3.2 by rails4 branch, which has
supported rails master branch only.
Still a lot of duplicate source code and these failures, though.
https://gist.github.com/yahonda/5127180

--
Yasuo Honda