Override methods for sharding connection

Hotfix - #869 - fixes for type conversion logic

#869 - DBAL-1293 - Making sure `Type::getType('dateinterval')` retrieves a `DateIntervalType` instance

#869 - DBAL-1293 - Correcting tests around the invalid date/time formats to use `setExpectedException`

Make date and time types throw exception when invalid values are passed to convertToDatabaseValue

drop php 5.3 support

requiresSQLCommentHint in DateIntervalType

According to comment https://github.com/doctrine/dbal/pull/854#issuecomment-126935212

Typo fixes

[DBAL-1220] Fix dropping database with active connection on PostgreSQL