Mobile App STACK4 with a D backend

[extrawurst]

Additionally these are the open source utility libs that I 
created to while developing the server:

google cloud messaging helper lib:
https://github.com/Extrawurst/gcm-d

sockjs long polling implementation based on vibe.d:
https://github.com/Extrawurst/sockjs-d

tool to keep the server running no matter what:
https://github.com/Extrawurst/forever-d

simple elo calculation:
https://github.com/Extrawurst/elo-rating-d

XTEA (Extended Tiny Encryption Algorithm) Implemenation in D:
https://github.com/Extrawurst/xtea-d