[J15] backport getConnection() method for databases, _resource is renamed and private in J17
[J15] backport getConnection() method for databases, _resource is renamed and private in J17

zooley/hubzero-cms,zweidner/hubzero-cms,zooley/hubzero-cms,zooley/hubzero-cms,zweidner/hubzero-cms,zooley/hubzero-cms,anthonyfuentes/hubzero-cms,zweidner/hubzero-cms,anthonyfuentes/hubzero-cms,anthonyfuentes/hubzero-cms,zweidner/hubzero-cms,anthonyfuentes/hubzero-cms