Change weird way of adding an entry to SplObjectStorage
Add DropSchemaSqlCollectorTest
Remove unused imports
Merge pull request #593 from JeroenDeDauw/unusedimps

Remove unused imports
fix order by with aggregate function(s) for limit/offset queries on SQL Server
Merge pull request #573 from deeky666/DBAL-834

[DBAL-834] Fix order by with aggregate function(s) for limit/offset queries on SQL Server
Fix style issue
Merge pull request #586 from JeroenDeDauw/DropSchemaSqlCollector

Change weird way of adding an entry to SplObjectStorage
Properly instantiate var and fix spelling.