Rails4 merges master 5th

This pull request merges master branch into rails4 branch.  

```ruby

$ git checkout rails4
Switched to branch 'rails4'
$ git checkout -b rails4_merges_master_5th
Switched to a new branch 'rails4_merges_master_5th'
2.0.0-p247@railsmaster [ rails4_merges_master_5th ~/git/oracle-enhanced]$ git merge master
Auto-merging activerecord-oracle_enhanced-adapter.gemspec
Merge made by recursive.
 History.md                                   |   21 +++++++++++++++++++++
 VERSION                                      |    2 +-
 activerecord-oracle_enhanced-adapter.gemspec |    4 ++--
 3 files changed, 24 insertions(+), 3 deletions(-)
$
```