Zend\Paginator\Adapter\DbSelect
First attempt at using subselect to calculate full count
Zend\Db & Zend\Paginator
- Paginator: removed clearing of columns from select
- Db\Sql\Select: when resettings columns, reset value should be array(self::SQL_STAR)
Zend\Paginator - added tests for DbSelect
Zend\Db\Sql\Select - reverted reset on column
Zend\Paginator
- reorganized the Mock setup for getItems and count tests to work
Merge branch 'hotfix/paginator-db-count-subselect' of https://github.com/ralphschindler/zf2 into develop

PR #4641
Closes #4590
Closes #3647