Zend\Db\Metadata\Source\AbstractSource Undefined index notices

(AbstractSource::getConstraintKeys): Add call to
child::loadConstraintReferences() and child::loadConstraintDataKeys()
to avoid triggering PHP notices for constraint_references and
constraint_keys
ZendTest\Db\Metadata\Source\SqliteMetadataTest

New unit test for #3719.
Add Docblocks and annotate unit test as #3719
[+BUGFIX] Fixed issue #4069

Oracle renders from table with alias incorrectly with "AS".
Modified implementation of Sql\Select and oracle specific
SelectDecorator to reflect the correct behavior
Zend\Db: Fixed metadata to directly quote values or use quoteTrustedValue()
Merge pull request #4241 from ralphschindler/hotfix/db-metadata-remove-quoting

Zend\Db\Metadata - remove quoting of known scalars, use quoteTrustedValue() for provided values
PR #3719 Merge branch 'develop' of git://github.com/ashawley/zf2 into ashawley-master
PR #4070 Merge branch 'hotfix/4069' of git://github.com/tux-rampage/zf2 into tux-rampage-hotfix/4069
Zend\Db\Sql Changed the name of new method renderTable() in Select object