[IMP] simplify finding out if a category is installed
[IMP] simplify finding out if a category is installed
gisce/openerp-web,splbio/openerp-web,MarkusTeufelberger/openerp-web,vnc-biz/openerp-web,vnc-biz/openerp-web,gisce/openerp-web,vnc-biz/openerp-web,splbio/openerp-web,vnc-biz/openerp-web,splbio/openerp-web,MarkusTeufelberger/openerp-web,gisce/openerp-web,MarkusTeufelberger/openerp-web