fix Firefox loading
more additional fixes of old changes
res.json('') -> valid JSON is empty string object: ""
fix 60e2acecb3d29f200322f7585461c69b7abaa75c
fix: "OOPS: restricted code in frontend"
rbac modules: fix when `userman` is not used (no auth)

fix c5e29d029f65ae616558ab2adb3c2b75a2b232fe
um.wes: new name of `um.backend.waitEvents`; rewrote/fixed state mgmnt
um.userman: fix UI loding and minor fixes after new `wes` and stuff
userman: handle session ending/relogin by UI (show login dlg)