added description field to cfps

closes #1650

done some changes

minor changes

added markdown format to cfp#show

fixed description text  position in proposals

fixed truncated description text in show action

minor changes on non-admin side

app/views/admin/cfps/_tracks_cfp.html.haml

@@ -10,6 +10,10 @@
   End Date:
 %dd#end_date
   = @cfp.end_date.strftime('%A, %B %-d. %Y')
+%dt
+  Description:
+%dd#description
+  = markdown(@cfp.description)
 %dt
   Days Left:
 %dd