view.desktop.Status: open ExtJS docs in new tab/window (when no mouse wheel click available)
store.CRUD: listen for proxy exceptions (and reader and model)

* reader if `success` is `false`
* model if constructor fails
(maybe more)
model.BaseCRUD: don't define `url` in class; fix undefined `cfg`

* first saves memory when models are oprated thru store
* second had blown up inside proxy reader when loading data from backend
  silently thus gave a clue to listen to proxy exceptions
CRUD: replay proxy config in model and store; fix model constructor call

* model.Base: fix that fancy Model.constructor
  this is actually plays with backend's JSON data
* model.Base, store.CRUD: save corrected `url` in `nw` case
* proxy.CRUD: no need in url in config
  total is there by default for JSON arrays
* model.chatUser: no need in `url`, store provides it and doesn't use
  Model's one
model.chatUser: split field config

`data.Reader` generates optimized functions for each field to read
CRUD: move exception listener into proxy config from store
CRUD.proxy: JSON optimized `Ext.data.reader.Json`

override data processing methods
- getResponseData()
- readRecords()

* crud_exception(): fill more description in error message
ExtJS defines: use class names not strings in data classes

this requires less const statics and gives more dynamic control
if execution order was lost and something isn't defined but used
userman create_auth(): update description
userman: add desc. to and style both `mwAuthenticate()` `create_auth()`
um.view.items_Bar: fix `view.Userman` launching