Rework rest handler

This is prototype of new n2o rest handler
POST is not implemented yet

https://github.com/b0oh/n2o_rest – example application
https://github.com/b0oh/n2o_rest/blob/master/apps/web/src/users.erl – rest module

Showcase
`open localhost:8000/rest/users`
`curl -i -H "Content-Type: application/x-www-form-urlencoded" -X PUT -d "id=5HT&email=5HT@synrc.com" localhost:8000/rest/users/maxim`
refresh browser
`curl -i -X DELETE localhost:8000/rest/users/5HT`
refresh browser