controller.Main: fix multiple `init()`
auth: prepare front, back, userman

start of '/login' stage impementation

* app.css: add general classes
* app_front run_frontend(): run `app_front_http` to connect
  to backend
* app_front_http: provide both contexts (browser && nw) with
  ExtJS configuration from app modules
* App.cfg.backend.url: no trailing slash
  (Connection.js, app_front.js, app_front_http.js, pingback.js)
  usage: `App.backend.req({ url: '/login' })`
* ctl.Main: provide `createViewport` event handling
   - handle by its own if no app module does
   - or via global event
  `- handleCreateViewport()` move code from `extjs_load.js`
   - `Ext.require` stuff from app modules
* extjs_load:
   - no devel mode, ExtJS loading is part of security model,
     thus `ext-all-debug.js` is used always,
     `ext-all-nw.js` has patched `loadScriptFile()` to work in `nw`
   - `Ext.Loader.getPath()`:
        `nw` fix for file loading from app modules:
        like "/l10n/ru_userman"
   - push `Main` controller in Application static init stage
   - `createViewport` event support
   - move viewport controlling in `ctl.Main`
   - `Ext.syncRequire()` boot staff from app modules
* l10n: add title, reload
* Desktop: remove testing `widget.useredit`
* Viewport: some touches

* cfg_default: provide controllers, requires

== Userman ==
* do subj
* app_back_userman: make pushing module files easy