[READY] Head to Head challenges / redesign Badges/My Challenges/Statistics

[Marthyn]

Fix #136 Fix #141 A lot of things will change in this pull request, i've been designing/thinking about this today. I want to implement Head to head challenges. Also i want to implement a way of betting points for a challenge, so why not combine the two:

A user can invite another user to do a H2Hchallenge on every problem, this will be async. The user who invites can set the amount of questions and the amount of points he wants to bet, the other user can accept or deny. They both can do the H2Hchallenge whenever they please and the winner will be based on the amount of good answered questions. The winner will get the amount of points bet back double(his own points and those of the losing user).

To make this happen there are a lot of changes necessary:

• [x] Invite view for H2H challenge
• [x] H2H challenge view for completing the challenge
• [x] Notification center (challenge invites will be notifications)
• [x] Challenges overview

• [x] Badges overview (with not completed badges in grey)
• [x] Answer handler for head to head challenges

[jurre]

Love that dog! <3

[Marthyn]

[jurre]

Awesome! Needs a driehoekje though!

[Marthyn]

click on the swords

[Marthyn]