use class, not klass, in widget.attrs

specify login form dom id, don't render progress div

backport crypto/captcha utilities from the registration cube

use an actual form for the login form ease customization from external cubes (eg rememberme)

add space between a checkbox and its label

ensure cnx is set first (necessary to introduce of a form object to handle the login form)

don't let set_schema making commit_event fail

use constant

fix permission of the condition permission

fix *_permissions schema: using the same cardinality/composite properties for cwgroup/rqlexpr leads to important pbs...

backport stable

DEFAULT_ATTRPERMS is now public

[inlined formos] don't pop attributes from kwargs, so they end-up in cw_extra_kwargs which is then passed to the edition form

[notification] we should use unsafe_execute here