Force lower case for user name mapping in ood_auth_map.regex

[jprorama]

The /opt/ood/ood_auth_map/bin/ood_auth_map.regex script needs to return a lower case username regardless of the case of the input name pattern.

It may be desirable to control this via a flag, like -d for downcase.

[jprorama]

The current tool only supports grep pattern matches and while they can be insensitive to case Ruby grep expressions cannot change the case. see also Ruby regex docs.