Challenges are placed in boxes
CSS changes to the files and the description
Tooltips for challenge categories
Challenges panels go green on success
Updated challenges page with countdown

refactoring metadata for challenges
Countdown can go into negatives
Merge branch 'master' into challenges-page-redesign

Conflicts:
	include/layout/layout.inc.php
Merge pull request #34 from Nakiami/challenges-page-redesign

Challenges page redesign