[IMP] base/rng: separator elements should have optional groups attribute Also refactored the groups attribute into a separate rng:define.
[IMP] base/rng: separator elements should have optional groups attribute
Also refactored the groups attribute into a separate rng:define.

gisce/openobject-server,gisce/openobject-server,MarkusTeufelberger/openobject-server,vnc-biz/openerp-server,gisce/openobject-server,ovnicraft/openerp-server,MarkusTeufelberger/openobject-server,vnc-biz/openerp-server,splbio/openobject-server,splbio/openobject-server,MarkusTeufelberger/openobject-server,splbio/openobject-server,ovnicraft/openerp-server