UI cleanup and fixes

app.htm:
 - fix error writing s/'<'/&lt;/, simpify `alert`
 -remove glitch when ExtJS is loaded: add 'margin:0;'

ctl.Main, extjs_load: fix first status message printing
Userman: if role combo is disabled then focus button
extjs_load: fix path for App && loading of backend classes for `nw`

`setPath()` for 'App' is useless, because there is `appFolder`
config, which is applied in `Ext.application()` later on
userman: if no session, reload UI
sendFile.js: fix `indexOf()` condition

thinko in 05eeb17def7aea5f7ce58ffadc5df3af9e786311
userman wait events: separate file and example broadcasts

* app_back_userman: use some broadcast()s, some other touches
* wait_events: move to its own lib file
 - methods: mwPutWaitEvents, broadcast, cleaup
 NOTE: res.on('close') and Firefox don't always work for some reason