HPCC-9035 - Support NAS flat configuration

Also, fixed:
1) Roxie's setup call, which was not picking
up the NAS section.
2) A bug meant ThorMaster wasn't having NAS setup

Signed-off-by: Jake Smith <jake.smith@lexisnexis.com>
Add missing ENVIRONMENT_API

Signed-off-by: Jake Smith <jake.smith@lexisnexis.com>
Merge pull request #4165 from jakesmith/hpcc-9035

HPCC-9035 - Support NAS flat configuration

Reviewed-By: Richard Chapman <rchapman@hpccsystems.com>