User account chapter select now uses checkboxes

Add back in some width to 'Skills' and 'Bio' textareas on profile page
delete account button is a fun red color
Move class level descriptions in-line

* Hoping that people will read them / pick better with in-line bullet points instead of gorgeous JS popovers.
* Also, futz with level descriptions a bit
Merge branch 'master' into inline-class-descriptions
Fix event class levels page's crashiness

Re-use class_levels partial on event class levels page
Convert some 'confirm:' options into 'data: { confirm:'
Show student and volunteer details on event page & email

- Add defaults for each field
Canonicalize installfest/docs URLs in student/vol details

Simplify "role_id ==" statements
Fix location chapter assignment

Make appropriate location attributes attr_accessible
Fill in volunteer details from their most recent RSVP
Redirect RSVP'd users that land on /learn or /volunteer to the event show page

Previously, if you had already RSVP'd to an event, then logged out,
clicked the Learn or Volunteer buttons on the event show page, and
logged in with the modal, you would be led to an RSVP
form that wouldn't actually work.

Now, a user in this situation is just redirected to the event show page
where they can decide for themselves their next course of action
(maybe editing their RSVP?).
Move volunteer RSVP attribute carryover logic into model
Preserve session attendance checkboxes when form validation fails

Migrate much logic related to the care and feeding of rsvp.rsvp_session_ids
toward the (sometimes simpler) assignment of rsvp.event_session_ids
Add attendee names CSV to organizer attendee detail page
Make ruby version less specific
Add Mavericks to operating systems
Remove patch level from ruby-version
Remove some UI cruft related to volunteer assignment
Merge pull request #212 from mehulkar/rubies

Make ruby version less specific
Add events count to chapter index page