[6.0 6.1 trunk] Impossible hide a field with manually created groups

Hello.

If you create a Group manually, and try to set this group to a field to hide itin debug mode. is impossible set it as group to a field due to xml restrictions.

<field name="comment" placeholder="Put an internal note..." groups="account.group_account_invoice"/>

Always list just groups created by code (with xml_id) as in the example.

IMHO is a problem cause security can no be managed always by a developer, in some cases (almost all medium implementations) you have experienced end users that can be able to set this kind of security but is technically impossible, at least taking more obvious way.

If i put:

<field name="comment" placeholder="Put an internal note..." groups="Name of Group"/>

It will explode.

Regard