Connection creation added to createStatement method for Pgsql.php.
Current schema
Default, unique and persistent connections
Charset support for connection
Fix for GitHub issue 3469
The configuration key for connection to Oracle Database was renamed from "instance" to "hostname".
syntax fix
:Merge branch 'master' into oracle_fix
remove '\' character from Traversable because already defined in 'use' statement
Merge branch 'hotfix/3663'

Close #3663
[#2899] Remove redundant method declaration

- Re-declaring a method as abstract when defined in an interface being
  implemented can lead to issues under some versions of PHP. Removing
  the abstract method in the abstract class fixes the issue.
Zend\Db\Sql
- Added Quantifier support to Zend\Db\Sql\Select (DISTINCT, ALL and Expression)
Make sure the NotEmpty validator is not already in chain
Merge branch 'oracle_fix' of git://github.com/hamilok/zf2 into hamilok-oracle_fix
Zend\Db\Adapter - OCI8 Connection
* Fixed up connect() method to allow looser connection options
* removed call_user_func() in favor of direct function calling
Merge branch 'hamilok-oracle_fix' into develop
Merge commit 'refs/pull/3681/head' of github.com:zendframework/zf2 into hotfix/declare-abstract-method
Merge pull request #3681 branch 'hotfix/declare-abstract-method' Fix #2899
Forward port #3681
fix invalid docblock
change @return  to @return ClassName
Merge branch 'master' of git://github.com/kitsemets/zf2 into kitsemets-master
Zend\Db\Adapter Pgsql
- cleaned up createStatement() for coding standards, removed excessive commented code