URBNG-35 Initial version of WebAPI - Hal+Json

From now response of actions ended with success are in Hal+Json format.
It's tested by only by hand, unit tests will be written soon.

So far WebApi has implemented:
* get root resource
* login
* register
* get list of games (needs 3 parameters: lat, lon and r passed by URL)
* get game static information
* get game dynamic information
* get user game status
but information included in response are useless, only format matters.