improvements from SAN Ouest Provence :

improvements from SAN Ouest Provence :
* introducing a category_type into categories. It can be A (adult), C (children), P (Professionnal), I (institution/organisation).
* each category_type has it's own forms to create members.
* the borrowers table has been heavily modified (many fields changed), to get something more logic & readable
* reintroducing guarantor/guanrantee system that is now independant from hardcoded C/A for categories
* updating templates to fit template rules

(see mail feb, 17 on koha-devel "new features for borrowers" for more details)