lib/response.js: provide `res.txt('text')` and `TextCSS` in `ContentTypes`

fix comments
lib/middleware/sendFile.js: rework for async and consisyent header setting
userman backend dep: import "mkdirp@0.3.5" by James Halliday

app module them selves may have node modules
config: fix comments
userman chat: text

* data/chat log directory in config; checking and creating it using 'mkdirp'
* sub api changed: `local` is hash of variables to live while sub api
  may reload; also there are can be `require`d modules
* `req.url.query` is parsed
* devel reload handles log file reset
* sub api can be async and sync

= text =

* chat post is simple `local.wes.broadcast('chatmsg@um', msg)`

* log file: check if date changed for it; write to it via write stream
  to prevent concurrent and or huge chunks writing collisions
* get log files by names

`text` was mostly developed using reload window tool, i.e. without big
node.js reloads
userman chat: text UI

chat root events (in, out, text) logic in controller, view structure
in MVC UI around backend's `local.wes.broadcast('chatmsg@um', msg)`

simple UI for simple backend

__ Developed, tested, debugged using reload `view.Window` tool button