DB -> Db
DB -> Db

- Renamed Zend\DB to Zend\Db; updated all dependent classes
- Also renamed all adapters to use MixedCase instead of ACRONYM case (PDO,
  MySQLi, etc.)

kynx/zend-cache,Maks3w/zend-cache,MadCat34/zend-cache,bvarent/zend-cache