Initial Ibm Db2 driver classes
Added working Ibm Db2 unit & integration tests
Removed references of PDO inside IbmDb2
Fixed unit test groups, various variable names in Zend\Db IbmDb2 driver
[#3517] CS fixes

- ran php-cs-fixer
[#3517] File and class-level docblocks

- Removed all @package, @subpackage, and @category annotations
- Ensure year is 2013
- Ensure all files have file-level docblocks
[#3517] ensure all class members have docblocks
Merge branch 'feature/3517' into develop

Close #3517
[Db] fixed use of two undefined classes/interfaces
Merge pull request #3524 from marc-mabe/hotfix/db_useOfUndefinedClasses

[2.1][Db] added two missing use statements