started work on join challenge options
Merge branch 'master' into challenge
added interface to join challenges
adding interface to create new challenges
Merge branch 'master' into challenge
ability to join invite only challenges
added options to create and manage challenges
display invite only details to challenge manager
fix to challenges filter
Merge branch 'master' into challenge

Conflicts:
	db/structure.sql
Added my challenge history view.
Added more links to challenges
Added upcoming challenges widget to dashboard.
Add ability to minimes dashboard widgets, minimisation persisists within sessions
Added upcoming challenges widget to dashboard.
Add ability to minimes dashboard widgets, minimisation persisists within sessions
asset compile and add more links to top nav bar