Default format for new DB in output reverted to ORA

The auto-generation of Condition DB schemas is reverted to construct by default the old layout (ORA). In order to generate output with the new format, the environment variable NEW_CONDDB has to be set.
Additional fixes concern:
- test for fronTier
- MetadataService error policy for non-existing tags

Packages involved:
CondCore/CondDB
CondCore/IOVService
CondCore/MetaDataService
CondCore/Utilities