Students get an email when they are promoted from the waitlist

This will happen if an event's size increases, or another
student cancels.
Fix intermittent errors for redirect

Add assertion of header before checking URL redirect

Fixes: https://www.pivotaltracker.com/story/show/49712465
Job details hint string discusses a wider range of jobs
Merge pull request #161 from eanakashima/master

Le'ts have the "what's your job" example string describe more jobs.
Merge pull request #162 from faun/fix_intermittent_failures

Fix intermittent errors for redirect
updated meetup message to SF Ruby
Merge pull request #163 from missherico/master

Change banner to say SFRuby
Use event's denormalized ends_at column to determine upcoming/past

Previously, we used 'event_sessions.ends_at', which can potentially
choose the wrong event_session for the source of ends_at.
Adding link to 'Class Breakdown' page on Org Dashboard

Includes a somewhat inauspicious and strange start to the Class Breakdown page

Adds backbone (via backbone-on-rails gem), jasmine, and a bunch of crazy .js files.
Remove reference to not-yet-existing /templates dir
Attend button now says Join the Waitlist if workshop is full
Signing up to a full event shows waitlist msg in email and flash
Add attendee role to checkins table

Also sets specific width percentages for the checkins table rows
to avoid ugliness when 'Un-check in' button pops in
Send reminders to confirmed students (not WLed)
Lurching slightly closer to student sorting

Adds handlebars_assets for backbone templates
Organizer can download student CSV
Merge branch 'student-reminder-email' of https://github.com/fionatay/bridge_troll into fionatay-student-reminder-email
Merge branch 'organizer-csv-download' of https://github.com/fionatay/bridge_troll into fionatay-organizer-csv-download
Volunteers will no longer be waitlisted when joining a full event
added course selection for organizers and students