Adds further support for Organisations, pretty much closing issue #12
Organisations can be created, edited, or deleted (currently by any users, as we don't have concept of User Roles yet)
New users and existing users can be given an organisation (though that doesn't mean much yet)
Users having an organisation is not yet mandatory, this kind of functionality will need to be reserved for when we look at User roles, as Super Users will not want an Organisation.
Drawing are still owned by users, and deleted once the user is deleted (see issue #53)
Adds further support for Organisations, pretty much closing issue #12
All members see this as we don't have roles yet
simple index of organisations
simple form for new/edit organisation