* Attempt to add registration confirmation
Using SRP auth mechanism, if server sent AUTH_MECHANISM_FIRST_SRP that means the player isn't exist.
Also tell player about the server and chosen username.
Local game has localhost as IP address of the server.
Add RenderingEngine::draw_menu_scene() to draw GUI and clouds background.
aborted -> connection_aborted
* Rewrite information message text
Client::promptConfirmRegister() -> Client::promptConfirmRegistration()
* Various code style fixes
* Use range based for loops
* Use empty instead of empty objects
* Use C++11 default keyword for trivial constructors and destructors
* Drop some useless casts
* Use emplace_back instead of push_back to improve performance of some vectors push
* Add Device3D class which will contain IrrlichtDevice interface
move getSupportedVideoDrivers to Device3D
Add Device3D singleton & use it in various places
Rename Device3D to Rendering engine & add helper functions to various device pointers
More singleton work
RenderingEngine owns draw_load_screen
move draw functions to RenderingEngine
Reduce IrrlichtDevice exposure and guienvironment
RenderingEngine: Expose get_timer_time() to remove device from guiEngine
Make irrlichtdevice & scene manager less exposed
* Code style fixes
* Move porting::getVideoDriverName, getVideoDriverFriendlyName, getDisplayDensity, getDisplaySize to RenderingEngine
Fix XORG_USED macro -> RenderingEngine + create_engine_device from RenderingEngine constructor directly
* enum paralax => enum parallax