Refactoring oxUserTest

Removing Unit_oxuserTest_oxutils2, as it is not used, removing setUp, as it will not be used anymore, refactoring setupUsers to createUser.
Refactoring oxUserTest

Using $oUser = $this->createUser(); instead of expecting that user will be created on setup.
Refactoring oxUserTest

Using $oUser = $this->createUser(); instead of expecting that user will be created on setup.
Refactoring oxUserTest

Changing modConfig::getInstance() to $this->getConfig()
Refactoring oxUserTest

Changing modSession::getInstance() to $this->getSession()
Refactoring oxUserTest

Changing oxDb::getDB() to $this->getDb()
Refactoring oxUserTest

Removing testGetUserSubshopAdmin, as it tests nothing, that method is non existing already, probably some leftover test.
Refactoring oxUserTest

Improving tearDown
changing return type to array