added date and time picker to submit form
need to fix picker
fixed datetimepicker by removing jquery scripts
logged in users can join events as challenger and/or spectator
added UI tweaks to joining events
minor changes to UI tweaks
if ownPost, the post page hides the join buttons
added lists of spectators and challengers
changed helper names
fixed notifications
initial layout for match up
Merge pull request #6 from songyeep/master

USBAT join event as Spectator and/or Challenger