[#1878] make (org|group)_member_create return dictized membership
[#1873] setup template variables at start of member_new controller

If a validation error was thrown, then the template would be rendered
before these variables had been setup.
Merge branch '1878-member_create_return_value' of https://github.com/joetsoi/ckan into joetsoi-1878-member_create_return_value
Merge branch 'joetsoi-1878-member_create_return_value'
Merge branch '1873-fix_group_member_controller' of https://github.com/joetsoi/ckan into joetsoi-1873-fix_group_member_controller
Merge branch 'joetsoi-1873-fix_group_member_controller'